21016604625654 has 128 divisors (see below), whose sum is σ = 47009198983680. Its totient is φ = 6209813376000.

The previous prime is 21016604625637. The next prime is 21016604625703. The reversal of 21016604625654 is 45652640661012.

It is a happy number.

It is a super-2 number, since 2×21016604625654² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1127672424 + ... + 1127691060.

It is an arithmetic number, because the mean of its divisors is an integer number (367259367060).

Almost surely, 2^{21016604625654} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21016604625654, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23504599491840).

21016604625654 is an abundant number, since it is smaller than the sum of its proper divisors (25992594358026).

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

21016604625654 is a wasteful number, since it uses less digits than its factorization.

21016604625654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20686.

The product of its (nonzero) digits is 2073600, while the sum is 48.

The spelling of 21016604625654 in words is "twenty-one trillion, sixteen billion, six hundred four million, six hundred twenty-five thousand, six hundred fifty-four".