51221307 has 8 divisors (see below), whose sum is σ = 68391184. Its totient is φ = 34099488.

The previous prime is 51221297. The next prime is 51221327. The reversal of 51221307 is 70312215.

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

It is not a de Polignac number, because 51221307 - 2⁶ = 51221243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51221327) 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, 9448 + ... + 13845.

It is an arithmetic number, because the mean of its divisors is an integer number (8548898).

Almost surely, 2^51221307 is an apocalyptic number.

51221307 is a deficient number, since it is larger than the sum of its proper divisors (17169877).

51221307 is a wasteful number, since it uses less digits than its factorization.

51221307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24029.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 51221307 is about 7156.9062450196. The cubic root of 51221307 is about 371.3786090940.

The spelling of 51221307 in words is "fifty-one million, two hundred twenty-one thousand, three hundred seven".