51721725399 has 8 divisors (see below), whose sum is σ = 68968104432. Its totient is φ = 34478248320.

The previous prime is 51721725397. The next prime is 51721725457. The reversal of 51721725399 is 99352712715.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51721725399 - 2¹ = 51721725397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51721725397) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 683554 + ... + 755439.

It is an arithmetic number, because the mean of its divisors is an integer number (8621013054).

Almost surely, 2^51721725399 is an apocalyptic number.

51721725399 is a deficient number, since it is larger than the sum of its proper divisors (17246379033).

51721725399 is a wasteful number, since it uses less digits than its factorization.

51721725399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450977.

The product of its digits is 1190700, while the sum is 51.

The spelling of 51721725399 in words is "fifty-one billion, seven hundred twenty-one million, seven hundred twenty-five thousand, three hundred ninety-nine".