51415531 has 4 divisors (see below), whose sum is σ = 54439992. Its totient is φ = 48391072.

The previous prime is 51415523. The next prime is 51415543. The reversal of 51415531 is 13551415.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51415531 - 2³ = 51415523 is a prime.

It is a super-2 number, since 2×51415531² = 5287113656023922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51415496 and 51415505.

It is not an unprimeable number, because it can be changed into a prime (51415561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1512205 + ... + 1512238.

It is an arithmetic number, because the mean of its divisors is an integer number (13609998).

Almost surely, 2^51415531 is an apocalyptic number.

51415531 is a deficient number, since it is larger than the sum of its proper divisors (3024461).

51415531 is a wasteful number, since it uses less digits than its factorization.

51415531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3024460.

The product of its digits is 1500, while the sum is 25.

The square root of 51415531 is about 7170.4623979211. The cubic root of 51415531 is about 371.8474222046.

Adding to 51415531 its reverse (13551415), we get a palindrome (64966946).

The spelling of 51415531 in words is "fifty-one million, four hundred fifteen thousand, five hundred thirty-one".