2551668 has 48 divisors (see below), whose sum is σ = 6996864. Its totient is φ = 708480.

The previous prime is 2551657. The next prime is 2551687. The reversal of 2551668 is 8661552.

It is a super-2 number, since 2×2551668² = 13022019164448, which contains 22 as substring.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2698 + ... + 3518.

It is an arithmetic number, because the mean of its divisors is an integer number (145768).

2^2551668 is an apocalyptic number.

2551668 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2551668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3498432).

2551668 is an abundant number, since it is smaller than the sum of its proper divisors (4445196).

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

2551668 is a wasteful number, since it uses less digits than its factorization.

2551668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872 (or 870 counting only the distinct ones).

The product of its digits is 14400, while the sum is 33.

The square root of 2551668 is about 1597.3941279471. The cubic root of 2551668 is about 136.6495027688.

The spelling of 2551668 in words is "two million, five hundred fifty-one thousand, six hundred sixty-eight".