1245747640 has 16 divisors (see below), whose sum is σ = 2802932280. Its totient is φ = 498299040.

The previous prime is 1245747637. The next prime is 1245747647. The reversal of 1245747640 is 467475421.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 31143691 = 1245747640 / (1 + 2 + 4 + 5 + 7 + 4 + 7 + 6 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 1245747593 and 1245747602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1245747647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15571806 + ... + 15571885.

Almost surely, 2^1245747640 is an apocalyptic number.

1245747640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1245747640 is an abundant number, since it is smaller than the sum of its proper divisors (1557184640).

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

1245747640 is a wasteful number, since it uses less digits than its factorization.

1245747640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31143702 (or 31143698 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 40.

The square root of 1245747640 is about 35295.1503750869. The cubic root of 1245747640 is about 1075.9944329761.

The spelling of 1245747640 in words is "one billion, two hundred forty-five million, seven hundred forty-seven thousand, six hundred forty".