18939540 has 48 divisors (see below), whose sum is σ = 54331200. Its totient is φ = 4926720.

The previous prime is 18939533. The next prime is 18939551. The reversal of 18939540 is 4593981.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1390 + ... + 6309.

It is an arithmetic number, because the mean of its divisors is an integer number (1131900).

Almost surely, 2^18939540 is an apocalyptic number.

18939540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18939540 is an abundant number, since it is smaller than the sum of its proper divisors (35391660).

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

18939540 is a wasteful number, since it uses less digits than its factorization.

18939540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7752 (or 7750 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 18939540 is about 4351.9581799461. The cubic root of 18939540 is about 266.5568262906.

The spelling of 18939540 in words is "eighteen million, nine hundred thirty-nine thousand, five hundred forty".