21487455396 has 81 divisors (see below), whose sum is σ = 59729067489. Its totient is φ = 6508418400.

The previous prime is 21487455391. The next prime is 21487455397. The reversal of 21487455396 is 69355478412.

It is a happy number.

The square root of 21487455396 is 146586.

It is a perfect power (a square), and thus also a powerful number.

21487455396 is a `hidden beast` number, since 2 + 1 + 4 + 87 + 4 + 553 + 9 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14571869796 + 6915585600 = 120714^2 + 83160^2 .

It is not an unprimeable number, because it can be changed into a prime (21487455391) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9673566 + ... + 9675786.

Almost surely, 2^21487455396 is an apocalyptic number.

21487455396 is the 146586-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21487455396

21487455396 is an abundant number, since it is smaller than the sum of its proper divisors (38241612093).

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

21487455396 is a wasteful number, since it uses less digits than its factorization.

21487455396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4474 (or 2237 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 54.

The spelling of 21487455396 in words is "twenty-one billion, four hundred eighty-seven million, four hundred fifty-five thousand, three hundred ninety-six".