21024521440 has 96 divisors (see below), whose sum is σ = 56306668320. Its totient is φ = 7354312704.

The previous prime is 21024521431. The next prime is 21024521461. The reversal of 21024521440 is 4412542012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 226479 + ... + 305518.

It is an arithmetic number, because the mean of its divisors is an integer number (586527795).

Almost surely, 2^21024521440 is an apocalyptic number.

21024521440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21024521440 is an abundant number, since it is smaller than the sum of its proper divisors (35282146880).

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

21024521440 is a wasteful number, since it uses less digits than its factorization.

21024521440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532044 (or 532036 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

The spelling of 21024521440 in words is "twenty-one billion, twenty-four million, five hundred twenty-one thousand, four hundred forty".