991269378 has 24 divisors (see below), whose sum is σ = 2343000816. Its totient is φ = 300384600.

The previous prime is 991269373. The next prime is 991269397. The reversal of 991269378 is 873962199.

991269378 is a `hidden beast` number, since 9 + 9 + 1 + 269 + 378 = 666.

It is a super-2 number, since 2×991269378² = 1965229959521013768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991269373) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2503008 + ... + 2503403.

It is an arithmetic number, because the mean of its divisors is an integer number (97625034).

Almost surely, 2^991269378 is an apocalyptic number.

991269378 is an abundant number, since it is smaller than the sum of its proper divisors (1351731438).

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

991269378 is a wasteful number, since it uses less digits than its factorization.

991269378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5006430 (or 5006427 counting only the distinct ones).

The product of its digits is 1469664, while the sum is 54.

The square root of 991269378 is about 31484.4307237720. The cubic root of 991269378 is about 997.0812820402.

The spelling of 991269378 in words is "nine hundred ninety-one million, two hundred sixty-nine thousand, three hundred seventy-eight".