161261206431 has 32 divisors (see below), whose sum is σ = 239494563840. Its totient is φ = 95847408000.

The previous prime is 161261206409. The next prime is 161261206451. The reversal of 161261206431 is 134602162161.

It is not a de Polignac number, because 161261206431 - 2¹³ = 161261198239 is a prime.

It is a super-2 number, since 2×161261206431² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161261206392 and 161261206401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161261206451) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 484356 + ... + 746406.

It is an arithmetic number, because the mean of its divisors is an integer number (7484205120).

Almost surely, 2^161261206431 is an apocalyptic number.

161261206431 is a deficient number, since it is larger than the sum of its proper divisors (78233357409).

161261206431 is a wasteful number, since it uses less digits than its factorization.

161261206431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262607.

The product of its (nonzero) digits is 10368, while the sum is 33.

Adding to 161261206431 its reverse (134602162161), we get a palindrome (295863368592).

The spelling of 161261206431 in words is "one hundred sixty-one billion, two hundred sixty-one million, two hundred six thousand, four hundred thirty-one".