1257649740 has 60 divisors (see below), whose sum is σ = 3945298896. Its totient is φ = 335372832.

The previous prime is 1257649727. The next prime is 1257649747. The reversal of 1257649740 is 479467521.

1257649740 is a `hidden beast` number, since 1 + 2 + 576 + 4 + 9 + 74 + 0 = 666.

1257649740 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1257649747) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 386544 + ... + 389783.

Almost surely, 2^1257649740 is an apocalyptic number.

1257649740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1257649740 is an abundant number, since it is smaller than the sum of its proper divisors (2687649156).

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

1257649740 is a wasteful number, since it uses less digits than its factorization.

1257649740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776348 (or 776337 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 45.

The square root of 1257649740 is about 35463.3577090495. The cubic root of 1257649740 is about 1079.4103262483.

The spelling of 1257649740 in words is "one billion, two hundred fifty-seven million, six hundred forty-nine thousand, seven hundred forty".