51668251 has 4 divisors (see below), whose sum is σ = 51704352. Its totient is φ = 51632152.

The previous prime is 51668249. The next prime is 51668261. The reversal of 51668251 is 15286615.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15286615 = 5 ⋅3057323.

It is a cyclic number.

It is not a de Polignac number, because 51668251 - 2¹ = 51668249 is a prime.

It is a super-2 number, since 2×51668251² = 5339216322798002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51668261) 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, 15811 + ... + 18796.

It is an arithmetic number, because the mean of its divisors is an integer number (12926088).

Almost surely, 2^51668251 is an apocalyptic number.

51668251 is a deficient number, since it is larger than the sum of its proper divisors (36101).

51668251 is a wasteful number, since it uses less digits than its factorization.

51668251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36100.

The product of its digits is 14400, while the sum is 34.

The square root of 51668251 is about 7188.0630909863. The cubic root of 51668251 is about 372.4556672913.

The spelling of 51668251 in words is "fifty-one million, six hundred sixty-eight thousand, two hundred fifty-one".