20835972 has 18 divisors (see below), whose sum is σ = 52668798. Its totient is φ = 6945312.

The previous prime is 20835967. The next prime is 20835977. The reversal of 20835972 is 27953802.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20835967) and next prime (20835977).

It can be written as a sum of positive squares in only one way, i.e., 16451136 + 4384836 = 4056^2 + 2094^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 578777 = 20835972 / (2 + 0 + 8 + 3 + 5 + 9 + 7 + 2).

It is not an unprimeable number, because it can be changed into a prime (20835977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 289353 + ... + 289424.

Almost surely, 2^20835972 is an apocalyptic number.

It is an amenable number.

20835972 is an abundant number, since it is smaller than the sum of its proper divisors (31832826).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20835972 is a wasteful number, since it uses less digits than its factorization.

20835972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578787 (or 578782 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 20835972 is about 4564.6436881755. The cubic root of 20835972 is about 275.1722204980.

The spelling of 20835972 in words is "twenty million, eight hundred thirty-five thousand, nine hundred seventy-two".