51113811 has 24 divisors (see below), whose sum is σ = 79555584. Its totient is φ = 29106000.

The previous prime is 51113789. The next prime is 51113813. The reversal of 51113811 is 11831115.

It is a happy number.

It is not a de Polignac number, because 51113811 - 2¹³ = 51105619 is a prime.

It is a super-2 number, since 2×51113811² = 5225243349887442, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (51113813) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 67686 + ... + 68436.

It is an arithmetic number, because the mean of its divisors is an integer number (3314816).

Almost surely, 2^51113811 is an apocalyptic number.

51113811 is a deficient number, since it is larger than the sum of its proper divisors (28441773).

51113811 is a wasteful number, since it uses less digits than its factorization.

51113811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231 (or 1224 counting only the distinct ones).

The product of its digits is 120, while the sum is 21.

The square root of 51113811 is about 7149.3923518017. The cubic root of 51113811 is about 371.1186282563.

Adding to 51113811 its reverse (11831115), we get a palindrome (62944926).

The spelling of 51113811 in words is "fifty-one million, one hundred thirteen thousand, eight hundred eleven".