21722581607 has 2 divisors, whose sum is σ = 21722581608. Its totient is φ = 21722581606.

The previous prime is 21722581579. The next prime is 21722581663. The reversal of 21722581607 is 70618522712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21722581607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21722581807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10861290803 + 10861290804.

It is an arithmetic number, because the mean of its divisors is an integer number (10861290804).

Almost surely, 2^21722581607 is an apocalyptic number.

21722581607 is a deficient number, since it is larger than the sum of its proper divisors (1).

21722581607 is an equidigital number, since it uses as much as digits as its factorization.

21722581607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 94080, while the sum is 41.

The spelling of 21722581607 in words is "twenty-one billion, seven hundred twenty-two million, five hundred eighty-one thousand, six hundred seven".