1501213991 has 2 divisors, whose sum is σ = 1501213992. Its totient is φ = 1501213990.

The previous prime is 1501213939. The next prime is 1501214021. The reversal of 1501213991 is 1993121051.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1501213991 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1501213891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 750606995 + 750606996.

It is an arithmetic number, because the mean of its divisors is an integer number (750606996).

Almost surely, 2^1501213991 is an apocalyptic number.

1501213991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1501213991 is an equidigital number, since it uses as much as digits as its factorization.

1501213991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2430, while the sum is 32.

The square root of 1501213991 is about 38745.5028487178. The cubic root of 1501213991 is about 1145.0229754548.

The spelling of 1501213991 in words is "one billion, five hundred one million, two hundred thirteen thousand, nine hundred ninety-one".