20191972 has 6 divisors (see below), whose sum is σ = 35335958. Its totient is φ = 10095984.

The previous prime is 20191931. The next prime is 20191987. The reversal of 20191972 is 27919102.

It can be written as a sum of positive squares in only one way, i.e., 14546596 + 5645376 = 3814^2 + 2376^2 .

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 as a sum of consecutive naturals, namely, 2523993 + ... + 2524000.

Almost surely, 2^20191972 is an apocalyptic number.

It is an amenable number.

20191972 is a deficient number, since it is larger than the sum of its proper divisors (15143986).

20191972 is a wasteful number, since it uses less digits than its factorization.

20191972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5047997 (or 5047995 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 20191972 is about 4493.5478188176. The cubic root of 20191972 is about 272.3074845947.

The spelling of 20191972 in words is "twenty million, one hundred ninety-one thousand, nine hundred seventy-two".