191438440 has 16 divisors (see below), whose sum is σ = 430736580. Its totient is φ = 76575360.

The previous prime is 191438419. The next prime is 191438449. The reversal of 191438440 is 44834191.

191438440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 188622756 + 2815684 = 13734^2 + 1678^2 .

It is a junction number, because it is equal to n+sod(n) for n = 191438396 and 191438405.

It is not an unprimeable number, because it can be changed into a prime (191438449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2392941 + ... + 2393020.

Almost surely, 2^191438440 is an apocalyptic number.

191438440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191438440 is an abundant number, since it is smaller than the sum of its proper divisors (239298140).

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

191438440 is a wasteful number, since it uses less digits than its factorization.

191438440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4785972 (or 4785968 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 191438440 is about 13836.1280711043. The cubic root of 191438440 is about 576.3368416230.

The spelling of 191438440 in words is "one hundred ninety-one million, four hundred thirty-eight thousand, four hundred forty".