161902171431 has 192 divisors, whose sum is σ = 341459629056. Its totient is φ = 71091302400.

The previous prime is 161902171429. The next prime is 161902171439. The reversal of 161902171431 is 134171209161.

161902171431 is a `hidden beast` number, since 1 + 6 + 1 + 9 + 0 + 217 + 1 + 431 = 666.

161902171431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161902171431 - 2¹ = 161902171429 is a prime.

It is a super-2 number, since 2×161902171431² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161902171439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5652376 + ... + 5680946.

It is an arithmetic number, because the mean of its divisors is an integer number (1778435568).

Almost surely, 2^161902171431 is an apocalyptic number.

161902171431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

161902171431 is an abundant number, since it is smaller than the sum of its proper divisors (179557457625).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161902171431 is a wasteful number, since it uses less digits than its factorization.

161902171431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28662 (or 28659 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

It can be divided in two parts, 161902 and 171431, that added together give a palindrome (333333).

The spelling of 161902171431 in words is "one hundred sixty-one billion, nine hundred two million, one hundred seventy-one thousand, four hundred thirty-one".