1256351563 has 8 divisors (see below), whose sum is σ = 1311408288. Its totient is φ = 1201330944.

The previous prime is 1256351491. The next prime is 1256351567. The reversal of 1256351563 is 3651536521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1256351563 - 2¹³ = 1256343371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256351567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81531 + ... + 95707.

It is an arithmetic number, because the mean of its divisors is an integer number (163926036).

Almost surely, 2^1256351563 is an apocalyptic number.

1256351563 is a deficient number, since it is larger than the sum of its proper divisors (55056725).

1256351563 is a wasteful number, since it uses less digits than its factorization.

1256351563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18053.

The product of its digits is 81000, while the sum is 37.

The square root of 1256351563 is about 35445.0499082735. The cubic root of 1256351563 is about 1079.0388004221.

The spelling of 1256351563 in words is "one billion, two hundred fifty-six million, three hundred fifty-one thousand, five hundred sixty-three".