16261321657 has 16 divisors (see below), whose sum is σ = 18633201664. Its totient is φ = 13901706000.

The previous prime is 16261321621. The next prime is 16261321679. The reversal of 16261321657 is 75612316261.

It is not a de Polignac number, because 16261321657 - 2¹⁵ = 16261288889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16261321357) 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, 5952982 + ... + 5955712.

It is an arithmetic number, because the mean of its divisors is an integer number (1164575104).

Almost surely, 2^16261321657 is an apocalyptic number.

It is an amenable number.

16261321657 is a deficient number, since it is larger than the sum of its proper divisors (2371880007).

16261321657 is a wasteful number, since it uses less digits than its factorization.

16261321657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4660.

The product of its digits is 90720, while the sum is 40.

The spelling of 16261321657 in words is "sixteen billion, two hundred sixty-one million, three hundred twenty-one thousand, six hundred fifty-seven".