21940770 has 16 divisors (see below), whose sum is σ = 52657920. Its totient is φ = 5850864.

The previous prime is 21940769. The next prime is 21940783. The reversal of 21940770 is 7704912.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 731359 = 21940770 / (2 + 1 + 9 + 4 + 0 + 7 + 7 + 0).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365650 + ... + 365709.

It is an arithmetic number, because the mean of its divisors is an integer number (3291120).

Almost surely, 2^21940770 is an apocalyptic number.

21940770 is an abundant number, since it is smaller than the sum of its proper divisors (30717150).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21940770 is a wasteful number, since it uses less digits than its factorization.

21940770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731369.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 21940770 is about 4684.0975651666. The cubic root of 21940770 is about 279.9522452571.

The spelling of 21940770 in words is "twenty-one million, nine hundred forty thousand, seven hundred seventy".