51109947 has 24 divisors (see below), whose sum is σ = 87499776. Its totient is φ = 29204712.

The previous prime is 51109921. The next prime is 51109963. The reversal of 51109947 is 74990115.

51109947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51109947 - 2⁷ = 51109819 is a prime.

It is a super-2 number, since 2×51109947² = 5224453364685618, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (51109907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13323 + ... + 16724.

It is an arithmetic number, because the mean of its divisors is an integer number (3645824).

Almost surely, 2^51109947 is an apocalyptic number.

51109947 is a deficient number, since it is larger than the sum of its proper divisors (36389829).

51109947 is an equidigital number, since it uses as much as digits as its factorization.

51109947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30069 (or 30057 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 36.

The square root of 51109947 is about 7149.1221139382. The cubic root of 51109947 is about 371.1092763252.

The spelling of 51109947 in words is "fifty-one million, one hundred nine thousand, nine hundred forty-seven".