51023581 has 4 divisors (see below), whose sum is σ = 58312672. Its totient is φ = 43734492.

The previous prime is 51023573. The next prime is 51023597. The reversal of 51023581 is 18532015.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51023581 - 2³ = 51023573 is a prime.

It is a super-2 number, since 2×51023581² = 5206811636127122, 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 (51023501) 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, 3644535 + ... + 3644548.

It is an arithmetic number, because the mean of its divisors is an integer number (14578168).

Almost surely, 2^51023581 is an apocalyptic number.

It is an amenable number.

51023581 is a deficient number, since it is larger than the sum of its proper divisors (7289091).

51023581 is an equidigital number, since it uses as much as digits as its factorization.

51023581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7289090.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 51023581 is about 7143.0792379757. The cubic root of 51023581 is about 370.9001239906.

Adding to 51023581 its reverse (18532015), we get a palindrome (69555596).

The spelling of 51023581 in words is "fifty-one million, twenty-three thousand, five hundred eighty-one".