18721542 has 32 divisors (see below), whose sum is σ = 43437312. Its totient is φ = 5268384.

The previous prime is 18721537. The next prime is 18721601. The reversal of 18721542 is 24512781.

It is a super-2 number, since 2×18721542² = 700992269715528, which contains 22 as substring.

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, 513 + ... + 6140.

It is an arithmetic number, because the mean of its divisors is an integer number (1357416).

Almost surely, 2^18721542 is an apocalyptic number.

18721542 is an abundant number, since it is smaller than the sum of its proper divisors (24715770).

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

18721542 is a wasteful number, since it uses less digits than its factorization.

18721542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6732.

The product of its digits is 4480, while the sum is 30.

The square root of 18721542 is about 4326.8397243254. The cubic root of 18721542 is about 265.5301691842.

The spelling of 18721542 in words is "eighteen million, seven hundred twenty-one thousand, five hundred forty-two".