51224399 has 4 divisors (see below), whose sum is σ = 53920440. Its totient is φ = 48528360.

The previous prime is 51224389. The next prime is 51224429. The reversal of 51224399 is 99342215.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51224399 is a prime.

It is a super-2 number, since 2×51224399² = 5247878105822402, 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 (51224359) 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, 1347992 + ... + 1348029.

It is an arithmetic number, because the mean of its divisors is an integer number (13480110).

Almost surely, 2^51224399 is an apocalyptic number.

51224399 is a deficient number, since it is larger than the sum of its proper divisors (2696041).

51224399 is a wasteful number, since it uses less digits than its factorization.

51224399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2696040.

The product of its digits is 19440, while the sum is 35.

The square root of 51224399 is about 7157.1222568851. The cubic root of 51224399 is about 371.3860817626.

The spelling of 51224399 in words is "fifty-one million, two hundred twenty-four thousand, three hundred ninety-nine".