21461078016 has 351 divisors, whose sum is σ = 72779746221. Its totient is φ = 6075482112.

The previous prime is 21461077997. The next prime is 21461078033. The reversal of 21461078016 is 61087016412.

It is a happy number.

The square root of 21461078016 is 146496.

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

21461078016 is a `hidden beast` number, since 21 + 4 + 610 + 7 + 8 + 0 + 16 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14958268416 + 6502809600 = 122304^2 + 80640^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 196890570 + ... + 196890678.

Almost surely, 2^21461078016 is an apocalyptic number.

21461078016 is the 146496-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21461078016

21461078016 is an abundant number, since it is smaller than the sum of its proper divisors (51318668205).

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

21461078016 is an equidigital number, since it uses as much as digits as its factorization.

21461078016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

Multiplying 21461078016 by its sum of digits (36), we get a square (772598808576 = 878976²).

21461078016 divided by its sum of digits (36) gives a square (596141056 = 24416²).

The spelling of 21461078016 in words is "twenty-one billion, four hundred sixty-one million, seventy-eight thousand, sixteen".