2645256421 has 4 divisors (see below), whose sum is σ = 2661485152. Its totient is φ = 2629027692.

The previous prime is 2645256401. The next prime is 2645256463. The reversal of 2645256421 is 1246525462.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2645256421 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 (2645256401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8114121 + ... + 8114446.

It is an arithmetic number, because the mean of its divisors is an integer number (665371288).

Almost surely, 2^2645256421 is an apocalyptic number.

It is an amenable number.

2645256421 is a deficient number, since it is larger than the sum of its proper divisors (16228731).

2645256421 is a wasteful number, since it uses less digits than its factorization.

2645256421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16228730.

The product of its digits is 115200, while the sum is 37.

The square root of 2645256421 is about 51432.0563559343. The cubic root of 2645256421 is about 1383.0013129845.

The spelling of 2645256421 in words is "two billion, six hundred forty-five million, two hundred fifty-six thousand, four hundred twenty-one".