1456640021 has 4 divisors (see below), whose sum is σ = 1456720044. Its totient is φ = 1456560000.

The previous prime is 1456639981. The next prime is 1456640023. The reversal of 1456640021 is 1200466541.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 854919121 + 601720900 = 29239^2 + 24530^2 .

It is a cyclic number.

It is not a de Polignac number, because 1456640021 - 2²² = 1452445717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1456640023) 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 3 ways as a sum of consecutive naturals, for example, 1991 + ... + 54011.

It is an arithmetic number, because the mean of its divisors is an integer number (364180011).

Almost surely, 2^1456640021 is an apocalyptic number.

It is an amenable number.

1456640021 is a deficient number, since it is larger than the sum of its proper divisors (80023).

1456640021 is an equidigital number, since it uses as much as digits as its factorization.

1456640021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80022.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 1456640021 is about 38165.9536891193. The cubic root of 1456640021 is about 1133.5762701724.

The spelling of 1456640021 in words is "one billion, four hundred fifty-six million, six hundred forty thousand, twenty-one".