999621907 has 2 divisors, whose sum is σ = 999621908. Its totient is φ = 999621906.

The previous prime is 999621899. The next prime is 999621911. The reversal of 999621907 is 709126999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999621907 - 2³ = 999621899 is a prime.

It is not a weakly prime, because it can be changed into another prime (999621937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499810953 + 499810954.

It is an arithmetic number, because the mean of its divisors is an integer number (499810954).

Almost surely, 2^999621907 is an apocalyptic number.

999621907 is a deficient number, since it is larger than the sum of its proper divisors (1).

999621907 is an equidigital number, since it uses as much as digits as its factorization.

999621907 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 551124, while the sum is 52.

The square root of 999621907 is about 31616.7978612636. The cubic root of 999621907 is about 999.8739531128.

The spelling of 999621907 in words is "nine hundred ninety-nine million, six hundred twenty-one thousand, nine hundred seven".