21970378 has 16 divisors (see below), whose sum is σ = 33985224. Its totient is φ = 10644480.

The previous prime is 21970373. The next prime is 21970387. The reversal of 21970378 is 87307912.

It can be written as a sum of positive squares in 4 ways, for example, as 17614809 + 4355569 = 4197^2 + 2087^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is not an unprimeable number, because it can be changed into a prime (21970373) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24498 + ... + 25378.

Almost surely, 2^21970378 is an apocalyptic number.

21970378 is a deficient number, since it is larger than the sum of its proper divisors (12014846).

21970378 is a wasteful number, since it uses less digits than its factorization.

21970378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1257.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 21970378 is about 4687.2569803671. The cubic root of 21970378 is about 280.0781159598.

The spelling of 21970378 in words is "twenty-one million, nine hundred seventy thousand, three hundred seventy-eight".