1255001891 has 16 divisors (see below), whose sum is σ = 1477018368. Its totient is φ = 1051284000.

The previous prime is 1255001887. The next prime is 1255001899. The reversal of 1255001891 is 1981005521.

It is not a de Polignac number, because 1255001891 - 2² = 1255001887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1255001899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76466 + ... + 91416.

It is an arithmetic number, because the mean of its divisors is an integer number (92313648).

Almost surely, 2^1255001891 is an apocalyptic number.

1255001891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1255001891 is a deficient number, since it is larger than the sum of its proper divisors (222016477).

1255001891 is a wasteful number, since it uses less digits than its factorization.

1255001891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15562.

The product of its (nonzero) digits is 3600, while the sum is 32.

The square root of 1255001891 is about 35426.0058572795. The cubic root of 1255001891 is about 1078.6522657614.

The spelling of 1255001891 in words is "one billion, two hundred fifty-five million, one thousand, eight hundred ninety-one".