630601991 has 2 divisors, whose sum is σ = 630601992. Its totient is φ = 630601990.

The previous prime is 630601973. The next prime is 630601999. The reversal of 630601991 is 199106036.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-630601991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (630601999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315300995 + 315300996.

It is an arithmetic number, because the mean of its divisors is an integer number (315300996).

Almost surely, 2^630601991 is an apocalyptic number.

630601991 is a deficient number, since it is larger than the sum of its proper divisors (1).

630601991 is an equidigital number, since it uses as much as digits as its factorization.

630601991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 630601991 is about 25111.7898804526. The cubic root of 630601991 is about 857.5348510118.

The spelling of 630601991 in words is "six hundred thirty million, six hundred one thousand, nine hundred ninety-one".