23989987 has 4 divisors (see below), whose sum is σ = 27417136. Its totient is φ = 20562840.

The previous prime is 23989981. The next prime is 23989991. The reversal of 23989987 is 78998932.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 23989987 - 2⁷ = 23989859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23989981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1713564 + ... + 1713577.

It is an arithmetic number, because the mean of its divisors is an integer number (6854284).

Almost surely, 2^23989987 is an apocalyptic number.

23989987 is a deficient number, since it is larger than the sum of its proper divisors (3427149).

23989987 is an equidigital number, since it uses as much as digits as its factorization.

23989987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3427148.

The product of its digits is 1959552, while the sum is 55.

The square root of 23989987 is about 4897.9574314198. The cubic root of 23989987 is about 288.4097939122.

It can be divided in two parts, 23989 and 987, that added together give a triangular number (24976 = T₂₂₃).

The spelling of 23989987 in words is "twenty-three million, nine hundred eighty-nine thousand, nine hundred eighty-seven".