21420388457136 has 30 divisors (see below), whose sum is σ = 59947337140860. Its totient is φ = 7140129485664.

The previous prime is 21420388457099. The next prime is 21420388457137. The reversal of 21420388457136 is 63175488302412.

21420388457136 is a `hidden beast` number, since 2 + 1 + 4 + 2 + 0 + 38 + 8 + 4 + 571 + 36 = 666.

It is not an unprimeable number, because it can be changed into a prime (21420388457137) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 74376348666 + ... + 74376348953.

It is an arithmetic number, because the mean of its divisors is an integer number (1998244571362).

Almost surely, 2^{21420388457136} is an apocalyptic number.

It is an amenable number.

21420388457136 is an abundant number, since it is smaller than the sum of its proper divisors (38526948683724).

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

21420388457136 is a wasteful number, since it uses less digits than its factorization.

21420388457136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148752697633 (or 148752697624 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 54.

The spelling of 21420388457136 in words is "twenty-one trillion, four hundred twenty billion, three hundred eighty-eight million, four hundred fifty-seven thousand, one hundred thirty-six".