51233240 has 64 divisors (see below), whose sum is σ = 124221600. Its totient is φ = 18946048.

The previous prime is 51233239. The next prime is 51233251. The reversal of 51233240 is 4233215.

51233240 = 1728² + 1729² + ... + 1744².

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39482 + ... + 40758.

Almost surely, 2^51233240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51233240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62110800).

51233240 is an abundant number, since it is smaller than the sum of its proper divisors (72988360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51233240 is a wasteful number, since it uses less digits than its factorization.

51233240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1364 (or 1360 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 51233240 is about 7157.7398667456. The cubic root of 51233240 is about 371.4074468121.

Adding to 51233240 its reverse (4233215), we get a palindrome (55466455).

The spelling of 51233240 in words is "fifty-one million, two hundred thirty-three thousand, two hundred forty".