2563121551 has 4 divisors (see below), whose sum is σ = 2563242192. Its totient is φ = 2563000912.

The previous prime is 2563121537. The next prime is 2563121557. The reversal of 2563121551 is 1551213652.

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 is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2563121551 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 (2563121557) 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, 19030 + ... + 74083.

It is an arithmetic number, because the mean of its divisors is an integer number (640810548).

Almost surely, 2^2563121551 is an apocalyptic number.

2563121551 is a deficient number, since it is larger than the sum of its proper divisors (120641).

2563121551 is an equidigital number, since it uses as much as digits as its factorization.

2563121551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120640.

The product of its digits is 9000, while the sum is 31.

The square root of 2563121551 is about 50627.2806992436. The cubic root of 2563121551 is about 1368.5365499502.

The spelling of 2563121551 in words is "two billion, five hundred sixty-three million, one hundred twenty-one thousand, five hundred fifty-one".