21365111970 has 96 divisors (see below), whose sum is σ = 56433386880. Its totient is φ = 5606979840.

The previous prime is 21365111969. The next prime is 21365112007. The reversal of 21365111970 is 7911156312.

It is a happy number.

21365111970 is a `hidden beast` number, since 2 + 136 + 511 + 1 + 9 + 7 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3939921 + ... + 3945339.

It is an arithmetic number, because the mean of its divisors is an integer number (587847780).

Almost surely, 2^21365111970 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21365111970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28216693440).

21365111970 is an abundant number, since it is smaller than the sum of its proper divisors (35068274910).

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

21365111970 is a wasteful number, since it uses less digits than its factorization.

21365111970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6120 (or 6117 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 36.

The spelling of 21365111970 in words is "twenty-one billion, three hundred sixty-five million, one hundred eleven thousand, nine hundred seventy".