20972818 has 8 divisors (see below), whose sum is σ = 31485312. Its totient is φ = 10477716.

The previous prime is 20972813. The next prime is 20972839. The reversal of 20972818 is 81827902.

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

It is a super-2 number, since 2×20972818² = 879718189722248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20972813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 730 + ... + 6517.

It is an arithmetic number, because the mean of its divisors is an integer number (3935664).

Almost surely, 2^20972818 is an apocalyptic number.

20972818 is a deficient number, since it is larger than the sum of its proper divisors (10512494).

20972818 is a wasteful number, since it uses less digits than its factorization.

20972818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8696.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 20972818 is about 4579.6089352695. The cubic root of 20972818 is about 275.7733296115.

The spelling of 20972818 in words is "twenty million, nine hundred seventy-two thousand, eight hundred eighteen".