21520005650 has 96 divisors (see below), whose sum is σ = 47196729216. Its totient is φ = 7197120000.

The previous prime is 21520005643. The next prime is 21520005653. The reversal of 21520005650 is 5650002512.

It is a super-2 number, since 2×21520005650² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (21520005653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2003795 + ... + 2014505.

It is an arithmetic number, because the mean of its divisors is an integer number (491632596).

Almost surely, 2^21520005650 is an apocalyptic number.

21520005650 is an abundant number, since it is smaller than the sum of its proper divisors (25676723566).

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

21520005650 is a wasteful number, since it uses less digits than its factorization.

21520005650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11028 (or 11023 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The spelling of 21520005650 in words is "twenty-one billion, five hundred twenty million, five thousand, six hundred fifty".