30991038723 has 16 divisors (see below), whose sum is σ = 45915985440. Its totient is φ = 20659191552.

The previous prime is 30991038697. The next prime is 30991038731. The reversal of 30991038723 is 32783019903.

It is not a de Polignac number, because 30991038723 - 2²² = 30986844419 is a prime.

It is a super-2 number, since 2×30991038723² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (30991038623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 436615 + ... + 502607.

It is an arithmetic number, because the mean of its divisors is an integer number (2869749090).

Almost surely, 2^30991038723 is an apocalyptic number.

30991038723 is a deficient number, since it is larger than the sum of its proper divisors (14924946717).

30991038723 is a wasteful number, since it uses less digits than its factorization.

30991038723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83395 (or 83389 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The spelling of 30991038723 in words is "thirty billion, nine hundred ninety-one million, thirty-eight thousand, seven hundred twenty-three".