18887961 has 16 divisors (see below), whose sum is σ = 26308800. Its totient is φ = 12038208.

The previous prime is 18887941. The next prime is 18887983. The reversal of 18887961 is 16978881.

It is not a de Polignac number, because 18887961 - 2⁵ = 18887929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18887961.

It is not an unprimeable number, because it can be changed into a prime (18887941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8295 + ... + 10323.

It is an arithmetic number, because the mean of its divisors is an integer number (1644300).

Almost surely, 2^18887961 is an apocalyptic number.

It is an amenable number.

18887961 is a deficient number, since it is larger than the sum of its proper divisors (7420839).

18887961 is a wasteful number, since it uses less digits than its factorization.

18887961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168.

The product of its digits is 193536, while the sum is 48.

The square root of 18887961 is about 4346.0281867471. The cubic root of 18887961 is about 266.3146304341.

The spelling of 18887961 in words is "eighteen million, eight hundred eighty-seven thousand, nine hundred sixty-one".