12551781 has 16 divisors (see below), whose sum is σ = 18704448. Its totient is φ = 7420800.

The previous prime is 12551779. The next prime is 12551783. The reversal of 12551781 is 18715521.

It is an interprime number because it is at equal distance from previous prime (12551779) and next prime (12551783).

It is not a de Polignac number, because 12551781 - 2¹ = 12551779 is a prime.

It is a super-2 number, since 2×12551781² = 315094412543922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12551783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3286 + ... + 5991.

It is an arithmetic number, because the mean of its divisors is an integer number (1169028).

Almost surely, 2^12551781 is an apocalyptic number.

12551781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12551781 is a deficient number, since it is larger than the sum of its proper divisors (6152667).

12551781 is a wasteful number, since it uses less digits than its factorization.

12551781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9332.

The product of its digits is 2800, while the sum is 30.

The square root of 12551781 is about 3542.8492770650. The cubic root of 12551781 is about 232.3994616763.

The spelling of 12551781 in words is "twelve million, five hundred fifty-one thousand, seven hundred eighty-one".