2251658778 has 16 divisors (see below), whose sum is σ = 4508880096. Its totient is φ = 749625840.

The previous prime is 2251658767. The next prime is 2251658809. The reversal of 2251658778 is 8778561522.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2251658778.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 226501 + ... + 236232.

It is an arithmetic number, because the mean of its divisors is an integer number (281805006).

Almost surely, 2^2251658778 is an apocalyptic number.

2251658778 is an abundant number, since it is smaller than the sum of its proper divisors (2257221318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2251658778 is a wasteful number, since it uses less digits than its factorization.

2251658778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463549.

The product of its digits is 1881600, while the sum is 51.

The square root of 2251658778 is about 47451.6467364411. The cubic root of 2251658778 is about 1310.6926349042.

The spelling of 2251658778 in words is "two billion, two hundred fifty-one million, six hundred fifty-eight thousand, seven hundred seventy-eight".