51111778 has 16 divisors (see below), whose sum is σ = 79744896. Its totient is φ = 24549840.

The previous prime is 51111761. The next prime is 51111787. The reversal of 51111778 is 87711115.

It is a super-2 number, since 2×51111778² = 5224827700642568, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 375 + ... + 10117.

It is an arithmetic number, because the mean of its divisors is an integer number (4984056).

Almost surely, 2^51111778 is an apocalyptic number.

51111778 is a deficient number, since it is larger than the sum of its proper divisors (28633118).

51111778 is a wasteful number, since it uses less digits than its factorization.

51111778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9849.

The product of its digits is 1960, while the sum is 31.

The square root of 51111778 is about 7149.2501704724. The cubic root of 51111778 is about 371.1137079020.

It can be divided in two parts, 5111 and 1778, that added together give a square (6889 = 83²).

The spelling of 51111778 in words is "fifty-one million, one hundred eleven thousand, seven hundred seventy-eight".