991929013 has 2 divisors, whose sum is σ = 991929014. Its totient is φ = 991929012.

The previous prime is 991928969. The next prime is 991929047. The reversal of 991929013 is 310929199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 923734449 + 68194564 = 30393^2 + 8258^2 .

It is a cyclic number.

It is not a de Polignac number, because 991929013 - 2²¹ = 989831861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991929053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495964506 + 495964507.

It is an arithmetic number, because the mean of its divisors is an integer number (495964507).

Almost surely, 2^991929013 is an apocalyptic number.

It is an amenable number.

991929013 is a deficient number, since it is larger than the sum of its proper divisors (1).

991929013 is an equidigital number, since it uses as much as digits as its factorization.

991929013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39366, while the sum is 43.

The square root of 991929013 is about 31494.9045561342. The cubic root of 991929013 is about 997.3024005005.

The spelling of 991929013 in words is "nine hundred ninety-one million, nine hundred twenty-nine thousand, thirteen".