21152640630 has 128 divisors (see below), whose sum is σ = 57385345536. Its totient is φ = 4944844800.

The previous prime is 21152640599. The next prime is 21152640671. The reversal of 21152640630 is 3604625112.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1372065 + ... + 1387395.

It is an arithmetic number, because the mean of its divisors is an integer number (448323012).

Almost surely, 2^21152640630 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21152640630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28692672768).

21152640630 is an abundant number, since it is smaller than the sum of its proper divisors (36232704906).

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

21152640630 is a wasteful number, since it uses less digits than its factorization.

21152640630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15502.

The product of its (nonzero) digits is 8640, while the sum is 30.

The spelling of 21152640630 in words is "twenty-one billion, one hundred fifty-two million, six hundred forty thousand, six hundred thirty".