20972001 has 4 divisors (see below), whose sum is σ = 27962672. Its totient is φ = 13981332.

The previous prime is 20971997. The next prime is 20972023. The reversal of 20972001 is 10027902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20972001 - 2² = 20971997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20972041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3495331 + ... + 3495336.

It is an arithmetic number, because the mean of its divisors is an integer number (6990668).

Almost surely, 2^20972001 is an apocalyptic number.

It is an amenable number.

20972001 is a deficient number, since it is larger than the sum of its proper divisors (6990671).

20972001 is an equidigital number, since it uses as much as digits as its factorization.

20972001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6990670.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 20972001 is about 4579.5197346447. The cubic root of 20972001 is about 275.7697486313.

Adding to 20972001 its reverse (10027902), we get a palindrome (30999903).

The spelling of 20972001 in words is "twenty million, nine hundred seventy-two thousand, one".