21323121929 has 2 divisors, whose sum is σ = 21323121930. Its totient is φ = 21323121928.

The previous prime is 21323121901. The next prime is 21323121961. The reversal of 21323121929 is 92912132312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13679641600 + 7643480329 = 116960^2 + 87427^2 .

It is a cyclic number.

It is not a de Polignac number, because 21323121929 - 2¹⁶ = 21323056393 is a prime.

It is not a weakly prime, because it can be changed into another prime (21323121979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661560964 + 10661560965.

It is an arithmetic number, because the mean of its divisors is an integer number (10661560965).

Almost surely, 2^21323121929 is an apocalyptic number.

It is an amenable number.

21323121929 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323121929 is an equidigital number, since it uses as much as digits as its factorization.

21323121929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 35.

The spelling of 21323121929 in words is "twenty-one billion, three hundred twenty-three million, one hundred twenty-one thousand, nine hundred twenty-nine".