21139211520 has 1296 divisors, whose sum is σ = 94147784640. Its totient is φ = 4514807808.

The previous prime is 21139211507. The next prime is 21139211531. The reversal of 21139211520 is 2511293112.

21139211520 is a `hidden beast` number, since 2 + 1 + 139 + 2 + 1 + 1 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (1296).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 289578204 + ... + 289578276.

Almost surely, 2^21139211520 is an apocalyptic number.

21139211520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21139211520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47073892320).

21139211520 is an abundant number, since it is smaller than the sum of its proper divisors (73008573120).

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

21139211520 is an equidigital number, since it uses as much as digits as its factorization.

21139211520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The spelling of 21139211520 in words is "twenty-one billion, one hundred thirty-nine million, two hundred eleven thousand, five hundred twenty".