991502139 has 32 divisors (see below), whose sum is σ = 1384750080. Its totient is φ = 630483200.

The previous prime is 991502131. The next prime is 991502143. The reversal of 991502139 is 931205199.

It is a cyclic number.

It is not a de Polignac number, because 991502139 - 2³ = 991502131 is a prime.

It is a super-3 number, since 3×991502139³ (a number of 28 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 991502097 and 991502106.

It is not an unprimeable number, because it can be changed into a prime (991502131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2300254 + ... + 2300684.

It is an arithmetic number, because the mean of its divisors is an integer number (43273440).

Almost surely, 2^991502139 is an apocalyptic number.

991502139 is a deficient number, since it is larger than the sum of its proper divisors (393247941).

991502139 is a wasteful number, since it uses less digits than its factorization.

991502139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 991502139 is about 31488.1269528691. The cubic root of 991502139 is about 997.1593178324.

The spelling of 991502139 in words is "nine hundred ninety-one million, five hundred two thousand, one hundred thirty-nine".