451928021 has 2 divisors, whose sum is σ = 451928022. Its totient is φ = 451928020.

The previous prime is 451928011. The next prime is 451928039. The reversal of 451928021 is 120829154.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 365344996 + 86583025 = 19114^2 + 9305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-451928021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (451928011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 225964010 + 225964011.

It is an arithmetic number, because the mean of its divisors is an integer number (225964011).

Almost surely, 2^451928021 is an apocalyptic number.

It is an amenable number.

451928021 is a deficient number, since it is larger than the sum of its proper divisors (1).

451928021 is an equidigital number, since it uses as much as digits as its factorization.

451928021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 451928021 is about 21258.5987543864. The cubic root of 451928021 is about 767.4022884163.

The spelling of 451928021 in words is "four hundred fifty-one million, nine hundred twenty-eight thousand, twenty-one".