645453400 has 24 divisors (see below), whose sum is σ = 1500679620. Its totient is φ = 258181280.

The previous prime is 645453373. The next prime is 645453469. The reversal of 645453400 is 4354546.

645453400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×645453400² = 833220183143120000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1613434 + ... + 1613833.

Almost surely, 2^645453400 is an apocalyptic number.

It is an amenable number.

645453400 is an abundant number, since it is smaller than the sum of its proper divisors (855226220).

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

645453400 is a wasteful number, since it uses less digits than its factorization.

645453400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3227283 (or 3227274 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 645453400 is about 25405.7749340578. The cubic root of 645453400 is about 864.2146635970.

The spelling of 645453400 in words is "six hundred forty-five million, four hundred fifty-three thousand, four hundred".