999951131 has 2 divisors, whose sum is σ = 999951132. Its totient is φ = 999951130.

The previous prime is 999951109. The next prime is 999951157. The reversal of 999951131 is 131159999.

It is a weak prime.

It is an emirp because it is prime and its reverse (131159999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999951131 is a prime.

It is a super-2 number, since 2×999951131² = 1999804528776358322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (999951181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499975565 + 499975566.

It is an arithmetic number, because the mean of its divisors is an integer number (499975566).

Almost surely, 2^999951131 is an apocalyptic number.

999951131 is a deficient number, since it is larger than the sum of its proper divisors (1).

999951131 is an equidigital number, since it uses as much as digits as its factorization.

999951131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98415, while the sum is 47.

The square root of 999951131 is about 31622.0039055086. The cubic root of 999951131 is about 999.9837100680.

The spelling of 999951131 in words is "nine hundred ninety-nine million, nine hundred fifty-one thousand, one hundred thirty-one".