1256863555 has 8 divisors (see below), whose sum is σ = 1543311792. Its totient is φ = 982107168.

The previous prime is 1256863541. The next prime is 1256863561. The reversal of 1256863555 is 5553686521.

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 1256863555 - 2⁹ = 1256863043 is a prime.

It is a super-4 number, since 4×1256863555⁴ (a number of 37 digits) contains 4444 as substring.

It is a Duffinian number.

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, 2922724 + ... + 2923153.

It is an arithmetic number, because the mean of its divisors is an integer number (192913974).

Almost surely, 2^1256863555 is an apocalyptic number.

1256863555 is a deficient number, since it is larger than the sum of its proper divisors (286448237).

1256863555 is an equidigital number, since it uses as much as digits as its factorization.

1256863555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5845925.

The product of its digits is 1080000, while the sum is 46.

The square root of 1256863555 is about 35452.2715069148. The cubic root of 1256863555 is about 1079.1853581798.

The spelling of 1256863555 in words is "one billion, two hundred fifty-six million, eight hundred sixty-three thousand, five hundred fifty-five".