18901881 has 12 divisors (see below), whose sum is σ = 28244580. Its totient is φ = 12166560.

The previous prime is 18901877. The next prime is 18901891. The reversal of 18901881 is 18810981.

It can be written as a sum of positive squares in 2 ways, for example, as 10949481 + 7952400 = 3309^2 + 2820^2 .

It is not a de Polignac number, because 18901881 - 2² = 18901877 is a prime.

It is a super-2 number, since 2×18901881² = 714562210676322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18901801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35950 + ... + 36471.

It is an arithmetic number, because the mean of its divisors is an integer number (2353715).

Almost surely, 2^18901881 is an apocalyptic number.

It is an amenable number.

18901881 is a deficient number, since it is larger than the sum of its proper divisors (9342699).

18901881 is a wasteful number, since it uses less digits than its factorization.

18901881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72456 (or 72453 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

The square root of 18901881 is about 4347.6293540273. The cubic root of 18901881 is about 266.3800369885.

The spelling of 18901881 in words is "eighteen million, nine hundred one thousand, eight hundred eighty-one".