21377015440 has 40 divisors (see below), whose sum is σ = 54219886848. Its totient is φ = 7773459840.

The previous prime is 21377015353. The next prime is 21377015447. The reversal of 21377015440 is 4451077312.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 21377015396 and 21377015405.

It is not an unprimeable number, because it can be changed into a prime (21377015447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12145152 + ... + 12146911.

Almost surely, 2^21377015440 is an apocalyptic number.

21377015440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21377015440 is an abundant number, since it is smaller than the sum of its proper divisors (32842871408).

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

21377015440 is a wasteful number, since it uses less digits than its factorization.

21377015440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24292087 (or 24292081 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 34.

The spelling of 21377015440 in words is "twenty-one billion, three hundred seventy-seven million, fifteen thousand, four hundred forty".