812457640 has 32 divisors (see below), whose sum is σ = 1872619560. Its totient is φ = 317056000.

The previous prime is 812457629. The next prime is 812457673. The reversal of 812457640 is 46754218.

It can be written as a sum of positive squares in 4 ways, for example, as 300883716 + 511573924 = 17346^2 + 22618^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 812457640.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246061 + ... + 249340.

Almost surely, 2^812457640 is an apocalyptic number.

It is an amenable number.

812457640 is an abundant number, since it is smaller than the sum of its proper divisors (1060161920).

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

812457640 is a wasteful number, since it uses less digits than its factorization.

812457640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495453 (or 495449 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 812457640 is about 28503.6425742395. The cubic root of 812457640 is about 933.1115725971. Note that the first 3 decimals are identical.

The spelling of 812457640 in words is "eight hundred twelve million, four hundred fifty-seven thousand, six hundred forty".