21001532120 has 64 divisors (see below), whose sum is σ = 47623140000. Its totient is φ = 8335019008.

The previous prime is 21001532099. The next prime is 21001532179. The reversal of 21001532120 is 2123510012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8539451 + ... + 8541909.

Almost surely, 2^21001532120 is an apocalyptic number.

21001532120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001532120 is an abundant number, since it is smaller than the sum of its proper divisors (26621607880).

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

21001532120 is a wasteful number, since it uses less digits than its factorization.

21001532120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4052 (or 4048 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The spelling of 21001532120 in words is "twenty-one billion, one million, five hundred thirty-two thousand, one hundred twenty".