391976145 has 32 divisors (see below), whose sum is σ = 760199040. Its totient is φ = 190048320.

The previous prime is 391976131. The next prime is 391976149. The reversal of 391976145 is 541679193.

It is not a de Polignac number, because 391976145 - 2¹⁶ = 391910609 is a prime.

It is a super-2 number, since 2×391976145² = 307290596498122050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 391976145.

It is not an unprimeable number, because it can be changed into a prime (391976149) 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, 130494 + ... + 133463.

It is an arithmetic number, because the mean of its divisors is an integer number (23756220).

Almost surely, 2^391976145 is an apocalyptic number.

It is an amenable number.

391976145 is a deficient number, since it is larger than the sum of its proper divisors (368222895).

391976145 is a wasteful number, since it uses less digits than its factorization.

391976145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263982 (or 263976 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 391976145 is about 19798.3874343341. The cubic root of 391976145 is about 731.8462959997.

The spelling of 391976145 in words is "three hundred ninety-one million, nine hundred seventy-six thousand, one hundred forty-five".