18913408 has 16 divisors (see below), whose sum is σ = 37679310. Its totient is φ = 9456640.

The previous prime is 18913403. The next prime is 18913457. The reversal of 18913408 is 80431981.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 16064064 + 2849344 = 4008^2 + 1688^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (18913403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 73753 + ... + 74008.

Almost surely, 2^18913408 is an apocalyptic number.

It is an amenable number.

18913408 is a deficient number, since it is larger than the sum of its proper divisors (18765902).

18913408 is an equidigital number, since it uses as much as digits as its factorization.

18913408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147775 (or 147763 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 18913408 is about 4348.9548169646. The cubic root of 18913408 is about 266.4341751405.

It can be divided in two parts, 18913 and 408, that added together give a square (19321 = 139²).

The spelling of 18913408 in words is "eighteen million, nine hundred thirteen thousand, four hundred eight".