21187083 has 16 divisors (see below), whose sum is σ = 30551040. Its totient is φ = 13009536.

The previous prime is 21187079. The next prime is 21187091. The reversal of 21187083 is 38078112.

It is a happy number.

It is not a de Polignac number, because 21187083 - 2² = 21187079 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21187083.

It is not an unprimeable number, because it can be changed into a prime (21187013) 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, 2023 + ... + 6816.

It is an arithmetic number, because the mean of its divisors is an integer number (1909440).

Almost surely, 2^21187083 is an apocalyptic number.

21187083 is a deficient number, since it is larger than the sum of its proper divisors (9363957).

21187083 is a wasteful number, since it uses less digits than its factorization.

21187083 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8906.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 21187083 is about 4602.9428629954. The cubic root of 21187083 is about 276.7092789319.

It can be divided in two parts, 2118708 and 3, that added together give a triangular number (2118711 = T₂₀₅₈).

The spelling of 21187083 in words is "twenty-one million, one hundred eighty-seven thousand, eighty-three".