161545125731 has 16 divisors (see below), whose sum is σ = 178795558656. Its totient is φ = 144724020000.

The previous prime is 161545125719. The next prime is 161545125751. The reversal of 161545125731 is 137521545161.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 161545125731 - 2¹⁸ = 161544863587 is a prime.

It is a super-2 number, since 2×161545125731² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161545125751) 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, 1688036 + ... + 1781166.

It is an arithmetic number, because the mean of its divisors is an integer number (11174722416).

Almost surely, 2^161545125731 is an apocalyptic number.

161545125731 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

161545125731 is a deficient number, since it is larger than the sum of its proper divisors (17250432925).

161545125731 is a wasteful number, since it uses less digits than its factorization.

161545125731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95434.

The product of its digits is 126000, while the sum is 41.

The spelling of 161545125731 in words is "one hundred sixty-one billion, five hundred forty-five million, one hundred twenty-five thousand, seven hundred thirty-one".