20101972 has 36 divisors (see below), whose sum is σ = 39649428. Its totient is φ = 8905600.

The previous prime is 20101951. The next prime is 20101979. The reversal of 20101972 is 27910102.

It can be written as a sum of positive squares in 2 ways, for example, as 352836 + 19749136 = 594^2 + 4444^2 .

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19338 + ... + 20350.

It is an arithmetic number, because the mean of its divisors is an integer number (1101373).

Almost surely, 2^20101972 is an apocalyptic number.

20101972 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

20101972 is a deficient number, since it is larger than the sum of its proper divisors (19547456).

20101972 is a wasteful number, since it uses less digits than its factorization.

20101972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080 (or 1067 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 20101972 is about 4483.5222760682. The cubic root of 20101972 is about 271.9023041587.

The spelling of 20101972 in words is "twenty million, one hundred one thousand, nine hundred seventy-two".