21620613550 has 24 divisors (see below), whose sum is σ = 40219441416. Its totient is φ = 8647148640.

The previous prime is 21620613533. The next prime is 21620613569. The reversal of 21620613550 is 5531602612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 454704 + ... + 499996.

It is an arithmetic number, because the mean of its divisors is an integer number (1675810059).

Almost surely, 2^21620613550 is an apocalyptic number.

21620613550 is a deficient number, since it is larger than the sum of its proper divisors (18598827866).

21620613550 is a wasteful number, since it uses less digits than its factorization.

21620613550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54852 (or 54847 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The spelling of 21620613550 in words is "twenty-one billion, six hundred twenty million, six hundred thirteen thousand, five hundred fifty".