2640625 has 21 divisors (see below), whose sum is σ = 3574173. Its totient is φ = 1950000.

The previous prime is 2640581. The next prime is 2640643. The reversal of 2640625 is 5260462.

The square root of 2640625 is 1625.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 10 ways, for example, as 1238769 + 1401856 = 1113^2 + 1184^2 .

It is not a de Polignac number, because 2640625 - 2⁷ = 2640497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2640625.

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 203119 + ... + 203131.

2^2640625 is an apocalyptic number.

2640625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2640625 is the 1625-th square number.

2640625 is the 813-rd centered octagonal number.

It is an amenable number.

2640625 is a deficient number, since it is larger than the sum of its proper divisors (933548).

2640625 is an frugal number, since it uses more digits than its factorization.

2640625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The cubic root of 2640625 is about 138.2193703420.

Multiplying 2640625 by its sum of digits (25), we get a square (66015625 = 8125²).

2640625 divided by its sum of digits (25) gives a square (105625 = 325²).

The spelling of 2640625 in words is "two million, six hundred forty thousand, six hundred twenty-five".