21138086 has 8 divisors (see below), whose sum is σ = 32227104. Its totient is φ = 10395720.

The previous prime is 21138077. The next prime is 21138101. The reversal of 21138086 is 68083112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86510 + ... + 86753.

It is an arithmetic number, because the mean of its divisors is an integer number (4028388).

Almost surely, 2^21138086 is an apocalyptic number.

21138086 is a deficient number, since it is larger than the sum of its proper divisors (11089018).

21138086 is a wasteful number, since it uses less digits than its factorization.

21138086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173326.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 21138086 is about 4597.6174264504. The cubic root of 21138086 is about 276.4958094123.

The spelling of 21138086 in words is "twenty-one million, one hundred thirty-eight thousand, eighty-six".