12551891 has 4 divisors (see below), whose sum is σ = 13692984. Its totient is φ = 11410800.

The previous prime is 12551881. The next prime is 12551893. The reversal of 12551891 is 19815521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19815521 = 11 ⋅1801411.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12551891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12551893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 570530 + ... + 570551.

It is an arithmetic number, because the mean of its divisors is an integer number (3423246).

Almost surely, 2^12551891 is an apocalyptic number.

12551891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12551891 is a deficient number, since it is larger than the sum of its proper divisors (1141093).

12551891 is a wasteful number, since it uses less digits than its factorization.

12551891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1141092.

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

The square root of 12551891 is about 3542.8648012590. The cubic root of 12551891 is about 232.4001405671.

The spelling of 12551891 in words is "twelve million, five hundred fifty-one thousand, eight hundred ninety-one".