623257640 has 32 divisors (see below), whose sum is σ = 1415205000. Its totient is φ = 247014144.

The previous prime is 623257631. The next prime is 623257643. The reversal of 623257640 is 46752326.

It can be written as a sum of positive squares in 4 ways, for example, as 546904996 + 76352644 = 23386^2 + 8738^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 623257640.

It is not an unprimeable number, because it can be changed into a prime (623257643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67115 + ... + 75834.

Almost surely, 2^623257640 is an apocalyptic number.

It is an amenable number.

623257640 is an abundant number, since it is smaller than the sum of its proper divisors (791947360).

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

623257640 is a wasteful number, since it uses less digits than its factorization.

623257640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143069 (or 143065 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 35.

The square root of 623257640 is about 24965.1284795412. The cubic root of 623257640 is about 854.1927289080.

The spelling of 623257640 in words is "six hundred twenty-three million, two hundred fifty-seven thousand, six hundred forty".