21101969929 has 2 divisors, whose sum is σ = 21101969930. Its totient is φ = 21101969928.

The previous prime is 21101969921. The next prime is 21101969953. The reversal of 21101969929 is 92996910112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20074639225 + 1027330704 = 141685^2 + 32052^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101969929 - 2³ = 21101969921 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101969921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550984964 + 10550984965.

It is an arithmetic number, because the mean of its divisors is an integer number (10550984965).

Almost surely, 2^21101969929 is an apocalyptic number.

It is an amenable number.

21101969929 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101969929 is an equidigital number, since it uses as much as digits as its factorization.

21101969929 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 157464, while the sum is 49.

The spelling of 21101969929 in words is "twenty-one billion, one hundred one million, nine hundred sixty-nine thousand, nine hundred twenty-nine".