51921207 has 12 divisors (see below), whose sum is σ = 80766504. Its totient is φ = 31951440.

The previous prime is 51921203. The next prime is 51921209. The reversal of 51921207 is 70212915.

It is not a de Polignac number, because 51921207 - 2² = 51921203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51921203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221769 + ... + 222002.

It is an arithmetic number, because the mean of its divisors is an integer number (6730542).

Almost surely, 2^51921207 is an apocalyptic number.

51921207 is a deficient number, since it is larger than the sum of its proper divisors (28845297).

51921207 is a wasteful number, since it uses less digits than its factorization.

51921207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443790 (or 443787 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 51921207 is about 7205.6371682177. The cubic root of 51921207 is about 373.0624974640.

The spelling of 51921207 in words is "fifty-one million, nine hundred twenty-one thousand, two hundred seven".