20451001 has 2 divisors, whose sum is σ = 20451002. Its totient is φ = 20451000.

The previous prime is 20450999. The next prime is 20451007. The reversal of 20451001 is 10015402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10989225 + 9461776 = 3315^2 + 3076^2 .

It is a cyclic number.

It is not a de Polignac number, because 20451001 - 2¹ = 20450999 is a prime.

Together with 20450999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20451007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10225500 + 10225501.

It is an arithmetic number, because the mean of its divisors is an integer number (10225501).

Almost surely, 2^20451001 is an apocalyptic number.

It is an amenable number.

20451001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20451001 is an equidigital number, since it uses as much as digits as its factorization.

20451001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 20451001 is about 4522.2782974956. The cubic root of 20451001 is about 273.4669561149.

Adding to 20451001 its reverse (10015402), we get a palindrome (30466403).

The spelling of 20451001 in words is "twenty million, four hundred fifty-one thousand, one".