2551016621 has 4 divisors (see below), whose sum is σ = 2563836000. Its totient is φ = 2538197244.

The previous prime is 2551016599. The next prime is 2551016623. The reversal of 2551016621 is 1266101552.

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 not a de Polignac number, because 2551016621 - 2¹⁴ = 2551000237 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 (2551016623) 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, 6409391 + ... + 6409788.

It is an arithmetic number, because the mean of its divisors is an integer number (640959000).

Almost surely, 2^2551016621 is an apocalyptic number.

It is an amenable number.

2551016621 is a deficient number, since it is larger than the sum of its proper divisors (12819379).

2551016621 is a wasteful number, since it uses less digits than its factorization.

2551016621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12819378.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 2551016621 is about 50507.5897365931. The cubic root of 2551016621 is about 1366.3787401046.

The spelling of 2551016621 in words is "two billion, five hundred fifty-one million, sixteen thousand, six hundred twenty-one".