40640625 has 63 divisors (see below), whose sum is σ = 77948221. Its totient is φ = 20400000.

The previous prime is 40640623. The next prime is 40640647. The reversal of 40640625 is 52604604.

It is a happy number.

The square root of 40640625 is 6375.

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 39955041 + 685584 = 6321^2 + 828^2 .

It is not a de Polignac number, because 40640625 - 2¹ = 40640623 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40640623) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 2390617 + ... + 2390633.

Almost surely, 2^40640625 is an apocalyptic number.

40640625 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

40640625 is the 6375-th square number.

40640625 is the 3188-th centered octagonal number.

It is an amenable number.

40640625 is a deficient number, since it is larger than the sum of its proper divisors (37307596).

40640625 is an frugal number, since it uses more digits than its factorization.

40640625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70 (or 25 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The cubic root of 40640625 is about 343.8112838395.

The spelling of 40640625 in words is "forty million, six hundred forty thousand, six hundred twenty-five".