991365378 has 16 divisors (see below), whose sum is σ = 1983155616. Its totient is φ = 330384320.

The previous prime is 991365329. The next prime is 991365449. The reversal of 991365378 is 873563199.

It is a self number, because there is not a number n which added to its sum of digits gives 991365378.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18250 + ... + 48122.

It is an arithmetic number, because the mean of its divisors is an integer number (123947226).

Almost surely, 2^991365378 is an apocalyptic number.

991365378 is an abundant number, since it is smaller than the sum of its proper divisors (991790238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991365378 is a wasteful number, since it uses less digits than its factorization.

991365378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35409.

The product of its digits is 1224720, while the sum is 51.

The square root of 991365378 is about 31485.9552499206. The cubic root of 991365378 is about 997.1134686202.

The spelling of 991365378 in words is "nine hundred ninety-one million, three hundred sixty-five thousand, three hundred seventy-eight".