21509011040 has 48 divisors (see below), whose sum is σ = 55434592080. Its totient is φ = 7821457920.

The previous prime is 21509011019. The next prime is 21509011061. The reversal of 21509011040 is 4011090512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21509011019) and next prime (21509011061).

It is a super-3 number, since 3×21509011040³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21509010997 and 21509011015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6108755 + ... + 6112274.

It is an arithmetic number, because the mean of its divisors is an integer number (1154887335).

Almost surely, 2^21509011040 is an apocalyptic number.

21509011040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21509011040 is an abundant number, since it is smaller than the sum of its proper divisors (33925581040).

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

21509011040 is a wasteful number, since it uses less digits than its factorization.

21509011040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12221055 (or 12221047 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 23.

The spelling of 21509011040 in words is "twenty-one billion, five hundred nine million, eleven thousand, forty".