51994391 has 4 divisors (see below), whose sum is σ = 52030800. Its totient is φ = 51957984.

The previous prime is 51994373. The next prime is 51994427. The reversal of 51994391 is 19349915.

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-51994391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51994301) 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, 15971 + ... + 18948.

It is an arithmetic number, because the mean of its divisors is an integer number (13007700).

Almost surely, 2^51994391 is an apocalyptic number.

51994391 is a deficient number, since it is larger than the sum of its proper divisors (36409).

51994391 is a wasteful number, since it uses less digits than its factorization.

51994391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36408.

The product of its digits is 43740, while the sum is 41.

The square root of 51994391 is about 7210.7136262647. The cubic root of 51994391 is about 373.2376949075.

The spelling of 51994391 in words is "fifty-one million, nine hundred ninety-four thousand, three hundred ninety-one".