18721896 has 32 divisors (see below), whose sum is σ = 49559040. Its totient is φ = 5873408.

The previous prime is 18721891. The next prime is 18721903. The reversal of 18721896 is 69812781.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (18721891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22536 + ... + 23351.

It is an arithmetic number, because the mean of its divisors is an integer number (1548720).

Almost surely, 2^18721896 is an apocalyptic number.

It is an amenable number.

18721896 is an abundant number, since it is smaller than the sum of its proper divisors (30837144).

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

18721896 is a wasteful number, since it uses less digits than its factorization.

18721896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45913 (or 45909 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 18721896 is about 4326.8806315867. The cubic root of 18721896 is about 265.5318427837.

The spelling of 18721896 in words is "eighteen million, seven hundred twenty-one thousand, eight hundred ninety-six".