21136378 has 8 divisors (see below), whose sum is σ = 32224500. Its totient is φ = 10394880.

The previous prime is 21136369. The next prime is 21136393. The reversal of 21136378 is 87363112.

It can be written as a sum of positive squares in 2 ways, for example, as 21132409 + 3969 = 4597^2 + 63^2 .

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

It is a zygodrome in base 4.

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, 86503 + ... + 86746.

Almost surely, 2^21136378 is an apocalyptic number.

21136378 is a deficient number, since it is larger than the sum of its proper divisors (11088122).

21136378 is a wasteful number, since it uses less digits than its factorization.

21136378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173312.

The product of its digits is 6048, while the sum is 31.

The square root of 21136378 is about 4597.4316743156. The cubic root of 21136378 is about 276.4883620720.

The spelling of 21136378 in words is "twenty-one million, one hundred thirty-six thousand, three hundred seventy-eight".