21385137560 has 32 divisors (see below), whose sum is σ = 48126476160. Its totient is φ = 8552292096.

The previous prime is 21385137523. The next prime is 21385137563. The reversal of 21385137560 is 6573158312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385137563) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 150932 + ... + 256028.

It is an arithmetic number, because the mean of its divisors is an integer number (1503952380).

Almost surely, 2^21385137560 is an apocalyptic number.

21385137560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21385137560 is an abundant number, since it is smaller than the sum of its proper divisors (26741338600).

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

21385137560 is a wasteful number, since it uses less digits than its factorization.

21385137560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110195 (or 110191 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 21385137560 in words is "twenty-one billion, three hundred eighty-five million, one hundred thirty-seven thousand, five hundred sixty".