20947972 has 12 divisors (see below), whose sum is σ = 36741376. Its totient is φ = 10450440.

The previous prime is 20947939. The next prime is 20947973. The reversal of 20947972 is 27974902.

It is not an unprimeable number, because it can be changed into a prime (20947973) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3804 + ... + 7507.

Almost surely, 2^20947972 is an apocalyptic number.

It is an amenable number.

20947972 is a deficient number, since it is larger than the sum of its proper divisors (15793404).

20947972 is a wasteful number, since it uses less digits than its factorization.

20947972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11778 (or 11776 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 20947972 is about 4576.8954543446. The cubic root of 20947972 is about 275.6643858717.

The spelling of 20947972 in words is "twenty million, nine hundred forty-seven thousand, nine hundred seventy-two".