2556667421 has 16 divisors (see below), whose sum is σ = 3190969728. Its totient is φ = 1990060800.

The previous prime is 2556667411. The next prime is 2556667429. The reversal of 2556667421 is 1247666552.

It is a de Polignac number, because none of the positive numbers 2^k-2556667421 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 (2556667429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55961 + ... + 90801.

It is an arithmetic number, because the mean of its divisors is an integer number (199435608).

Almost surely, 2^2556667421 is an apocalyptic number.

It is an amenable number.

2556667421 is a deficient number, since it is larger than the sum of its proper divisors (634302307).

2556667421 is a wasteful number, since it uses less digits than its factorization.

2556667421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35812.

The product of its digits is 604800, while the sum is 44.

The square root of 2556667421 is about 50563.4988998981. The cubic root of 2556667421 is about 1367.3868922867.

The spelling of 2556667421 in words is "two billion, five hundred fifty-six million, six hundred sixty-seven thousand, four hundred twenty-one".