51691299 has 8 divisors (see below), whose sum is σ = 75187392. Its totient is φ = 31328040.

The previous prime is 51691279. The next prime is 51691307. The reversal of 51691299 is 99219615.

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 51691299 - 2¹⁵ = 51658531 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51691299.

It is not an unprimeable number, because it can be changed into a prime (51691259) 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, 783169 + ... + 783234.

It is an arithmetic number, because the mean of its divisors is an integer number (9398424).

Almost surely, 2^51691299 is an apocalyptic number.

51691299 is a deficient number, since it is larger than the sum of its proper divisors (23496093).

51691299 is a wasteful number, since it uses less digits than its factorization.

51691299 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566417.

The product of its digits is 43740, while the sum is 42.

The square root of 51691299 is about 7189.6661257669. Note that the first 3 decimals coincide. The cubic root of 51691299 is about 372.5110403166.

The spelling of 51691299 in words is "fifty-one million, six hundred ninety-one thousand, two hundred ninety-nine".