2161531405031 has 16 divisors (see below), whose sum is σ = 2233838005920. Its totient is φ = 2090559052800.

The previous prime is 2161531405003. The next prime is 2161531405037. The reversal of 2161531405031 is 1305041351612.

It is a cyclic number.

It is not a de Polignac number, because 2161531405031 - 2¹⁸ = 2161531142887 is a prime.

It is a super-2 number, since 2×2161531405031² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161531405037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1101341 + ... + 2352873.

It is an arithmetic number, because the mean of its divisors is an integer number (139614875370).

Almost surely, 2^{2161531405031} is an apocalyptic number.

2161531405031 is a deficient number, since it is larger than the sum of its proper divisors (72306600889).

2161531405031 is a wasteful number, since it uses less digits than its factorization.

2161531405031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1252066.

The product of its (nonzero) digits is 10800, while the sum is 32.

Adding to 2161531405031 its reverse (1305041351612), we get a palindrome (3466572756643).

The spelling of 2161531405031 in words is "two trillion, one hundred sixty-one billion, five hundred thirty-one million, four hundred five thousand, thirty-one".