81964628929 has 2 divisors, whose sum is σ = 81964628930. Its totient is φ = 81964628928.

The previous prime is 81964628899. The next prime is 81964628989. The reversal of 81964628929 is 92982646918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68780307600 + 13184321329 = 262260^2 + 114823^2 .

It is a cyclic number.

It is not a de Polignac number, because 81964628929 - 2¹³ = 81964620737 is a prime.

It is not a weakly prime, because it can be changed into another prime (81964628989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40982314464 + 40982314465.

It is an arithmetic number, because the mean of its divisors is an integer number (40982314465).

Almost surely, 2^81964628929 is an apocalyptic number.

It is an amenable number.

81964628929 is a deficient number, since it is larger than the sum of its proper divisors (1).

81964628929 is an equidigital number, since it uses as much as digits as its factorization.

81964628929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26873856, while the sum is 64.

The spelling of 81964628929 in words is "eighty-one billion, nine hundred sixty-four million, six hundred twenty-eight thousand, nine hundred twenty-nine".