165151651521 has 16 divisors (see below), whose sum is σ = 220831116800. Its totient is φ = 109786866048.

The previous prime is 165151651517. The next prime is 165151651523. The reversal of 165151651521 is 125156151561.

It is not a de Polignac number, because 165151651521 - 2² = 165151651517 is a prime.

It is a super-2 number, since 2×165151651521² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165151651521.

It is not an unprimeable number, because it can be changed into a prime (165151651523) 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, 3111120 + ... + 3163758.

It is an arithmetic number, because the mean of its divisors is an integer number (13801944800).

Almost surely, 2^165151651521 is an apocalyptic number.

It is an amenable number.

165151651521 is a deficient number, since it is larger than the sum of its proper divisors (55679465279).

165151651521 is a wasteful number, since it uses less digits than its factorization.

165151651521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55608.

The product of its digits is 45000, while the sum is 39.

The spelling of 165151651521 in words is "one hundred sixty-five billion, one hundred fifty-one million, six hundred fifty-one thousand, five hundred twenty-one".