51673721 has 8 divisors (see below), whose sum is σ = 56930688. Its totient is φ = 46510000.

The previous prime is 51673703. The next prime is 51673723. The reversal of 51673721 is 12737615.

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

It is a cyclic number.

It is not a de Polignac number, because 51673721 - 2²² = 47479417 is a prime.

It is a super-3 number, since 3×51673721³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51673723) 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, 22145 + ... + 24366.

It is an arithmetic number, because the mean of its divisors is an integer number (7116336).

Almost surely, 2^51673721 is an apocalyptic number.

It is an amenable number.

51673721 is a deficient number, since it is larger than the sum of its proper divisors (5256967).

51673721 is a wasteful number, since it uses less digits than its factorization.

51673721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46623.

The product of its digits is 8820, while the sum is 32.

The square root of 51673721 is about 7188.4435728466. The cubic root of 51673721 is about 372.4688105051.

It can be divided in two parts, 5167 and 3721, that added together give a palindrome (8888).

The spelling of 51673721 in words is "fifty-one million, six hundred seventy-three thousand, seven hundred twenty-one".