51866919 has 16 divisors (see below), whose sum is σ = 82751200. Its totient is φ = 31917888.

The previous prime is 51866869. The next prime is 51866921. The reversal of 51866919 is 91966815.

It is not a de Polignac number, because 51866919 - 2⁷ = 51866791 is a prime.

It is a super-2 number, since 2×51866919² = 5380354573105122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51866929) 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, 73534 + ... + 74235.

It is an arithmetic number, because the mean of its divisors is an integer number (5171950).

Almost surely, 2^51866919 is an apocalyptic number.

51866919 is a deficient number, since it is larger than the sum of its proper divisors (30884281).

51866919 is a wasteful number, since it uses less digits than its factorization.

51866919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147791 (or 147785 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 51866919 is about 7201.8691323850. The cubic root of 51866919 is about 372.9324293550.

The spelling of 51866919 in words is "fifty-one million, eight hundred sixty-six thousand, nine hundred nineteen".