20972290 has 8 divisors (see below), whose sum is σ = 37750140. Its totient is φ = 8388912.

The previous prime is 20972269. The next prime is 20972291. The reversal of 20972290 is 9227902.

It can be written as a sum of positive squares in 2 ways, for example, as 20820969 + 151321 = 4563^2 + 389^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20972291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1048605 + ... + 1048624.

Almost surely, 2^20972290 is an apocalyptic number.

20972290 is a deficient number, since it is larger than the sum of its proper divisors (16777850).

20972290 is a wasteful number, since it uses less digits than its factorization.

20972290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2097236.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 20972290 is about 4579.5512880631. The cubic root of 20972290 is about 275.7710153534.

The spelling of 20972290 in words is "twenty million, nine hundred seventy-two thousand, two hundred ninety".