21356970907 has 2 divisors, whose sum is σ = 21356970908. Its totient is φ = 21356970906.

The previous prime is 21356970893. The next prime is 21356970911. The reversal of 21356970907 is 70907965312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21356970907 - 2⁷ = 21356970779 is a prime.

It is a super-2 number, since 2×21356970907² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21356970967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678485453 + 10678485454.

It is an arithmetic number, because the mean of its divisors is an integer number (10678485454).

Almost surely, 2^21356970907 is an apocalyptic number.

21356970907 is a deficient number, since it is larger than the sum of its proper divisors (1).

21356970907 is an equidigital number, since it uses as much as digits as its factorization.

21356970907 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 714420, while the sum is 49.

The spelling of 21356970907 in words is "twenty-one billion, three hundred fifty-six million, nine hundred seventy thousand, nine hundred seven".