1256222891 has 8 divisors (see below), whose sum is σ = 1566200064. Its totient is φ = 978874920.

The previous prime is 1256222887. The next prime is 1256222923. The reversal of 1256222891 is 1982226521.

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 1256222891 - 2² = 1256222887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1256222881) 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, 8157215 + ... + 8157368.

It is an arithmetic number, because the mean of its divisors is an integer number (195775008).

Almost surely, 2^1256222891 is an apocalyptic number.

1256222891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1256222891 is a deficient number, since it is larger than the sum of its proper divisors (309977173).

1256222891 is a wasteful number, since it uses less digits than its factorization.

1256222891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16314601.

The product of its digits is 34560, while the sum is 38.

The square root of 1256222891 is about 35443.2347705454. The cubic root of 1256222891 is about 1079.0019617896.

It can be divided in two parts, 12562 and 22891, that added together give a palindrome (35453).

The spelling of 1256222891 in words is "one billion, two hundred fifty-six million, two hundred twenty-two thousand, eight hundred ninety-one".