161651531 has 8 divisors (see below), whose sum is σ = 162816000. Its totient is φ = 160491240.

The previous prime is 161651527. The next prime is 161651533. The reversal of 161651531 is 135156161.

161651531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161651531 - 2² = 161651527 is a prime.

It is a super-2 number, since 2×161651531² = 52262434949287922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161651494 and 161651503.

It is not an unprimeable number, because it can be changed into a prime (161651533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125750 + ... + 127028.

It is an arithmetic number, because the mean of its divisors is an integer number (20352000).

Almost surely, 2^161651531 is an apocalyptic number.

161651531 is a deficient number, since it is larger than the sum of its proper divisors (1164469).

161651531 is a wasteful number, since it uses less digits than its factorization.

161651531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2089.

The product of its digits is 2700, while the sum is 29.

The square root of 161651531 is about 12714.2255367757. The cubic root of 161651531 is about 544.7450267632.

The spelling of 161651531 in words is "one hundred sixty-one million, six hundred fifty-one thousand, five hundred thirty-one".