18772640 has 24 divisors (see below), whose sum is σ = 44350740. Its totient is φ = 7508992.

The previous prime is 18772631. The next prime is 18772643. The reversal of 18772640 is 4627781.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16096144 + 2676496 = 4012^2 + 1636^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18772640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18772643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58505 + ... + 58824.

Almost surely, 2^18772640 is an apocalyptic number.

18772640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18772640 is an abundant number, since it is smaller than the sum of its proper divisors (25578100).

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

18772640 is a wasteful number, since it uses less digits than its factorization.

18772640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117344 (or 117336 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 18772640 is about 4332.7404722646. The cubic root of 18772640 is about 265.7715263542.

It can be divided in two parts, 187 and 72640, that added together give a palindrome (72827).

The spelling of 18772640 in words is "eighteen million, seven hundred seventy-two thousand, six hundred forty".