40297640 has 16 divisors (see below), whose sum is σ = 90669780. Its totient is φ = 16119040.

The previous prime is 40297639. The next prime is 40297657. The reversal of 40297640 is 4679204.

It can be written as a sum of positive squares in 2 ways, for example, as 40119556 + 178084 = 6334^2 + 422^2 .

It is a junction number, because it is equal to n+sod(n) for n = 40297597 and 40297606.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 503681 + ... + 503760.

Almost surely, 2^40297640 is an apocalyptic number.

40297640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

40297640 is an abundant number, since it is smaller than the sum of its proper divisors (50372140).

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

40297640 is a wasteful number, since it uses less digits than its factorization.

40297640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007452 (or 1007448 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 40297640 is about 6348.0422178810. The cubic root of 40297640 is about 342.8413560853.

The spelling of 40297640 in words is "forty million, two hundred ninety-seven thousand, six hundred forty".