1256347651 has 16 divisors (see below), whose sum is σ = 1434875904. Its totient is φ = 1089736704.

The previous prime is 1256347649. The next prime is 1256347661. The reversal of 1256347651 is 1567436521.

It is a cyclic number.

It is not a de Polignac number, because 1256347651 - 2¹ = 1256347649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256347601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 144510 + ... + 152956.

It is an arithmetic number, because the mean of its divisors is an integer number (89679744).

Almost surely, 2^1256347651 is an apocalyptic number.

1256347651 is a deficient number, since it is larger than the sum of its proper divisors (178528253).

1256347651 is a wasteful number, since it uses less digits than its factorization.

1256347651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150.

The product of its digits is 151200, while the sum is 40.

The square root of 1256347651 is about 35444.9947242202. The cubic root of 1256347651 is about 1079.0376804585.

The spelling of 1256347651 in words is "one billion, two hundred fifty-six million, three hundred forty-seven thousand, six hundred fifty-one".