16721253654 has 16 divisors (see below), whose sum is σ = 38220008448. Its totient is φ = 4777501032.

The previous prime is 16721253623. The next prime is 16721253683. The reversal of 16721253654 is 45635212761.

It is a super-2 number, since 2×16721253654² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 398125087 = 16721253654 / (1 + 6 + 7 + 2 + 1 + 2 + 5 + 3 + 6 + 5 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 199062502 + ... + 199062585.

It is an arithmetic number, because the mean of its divisors is an integer number (2388750528).

Almost surely, 2^16721253654 is an apocalyptic number.

16721253654 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

16721253654 is an abundant number, since it is smaller than the sum of its proper divisors (21498754794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16721253654 is a wasteful number, since it uses less digits than its factorization.

16721253654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398125099.

The product of its digits is 302400, while the sum is 42.

The spelling of 16721253654 in words is "sixteen billion, seven hundred twenty-one million, two hundred fifty-three thousand, six hundred fifty-four".