21695790870 has 224 divisors, whose sum is σ = 66380076000. Its totient is φ = 5059003392.

The previous prime is 21695790863. The next prime is 21695790929. The reversal of 21695790870 is 7809759612.

21695790870 is a `hidden beast` number, since 2 + 1 + 69 + 579 + 0 + 8 + 7 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 1794606 + ... + 1806654.

It is an arithmetic number, because the mean of its divisors is an integer number (296339625).

Almost surely, 2^21695790870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21695790870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33190038000).

21695790870 is an abundant number, since it is smaller than the sum of its proper divisors (44684285130).

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

21695790870 is a wasteful number, since it uses less digits than its factorization.

21695790870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12106 (or 12091 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 54.

The spelling of 21695790870 in words is "twenty-one billion, six hundred ninety-five million, seven hundred ninety thousand, eight hundred seventy".