51666031 has 4 divisors (see below), whose sum is σ = 51995272. Its totient is φ = 51336792.

The previous prime is 51666029. The next prime is 51666037. The reversal of 51666031 is 13066615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13066615 = 5 ⋅2613323.

It is a cyclic number.

It is not a de Polignac number, because 51666031 - 2¹ = 51666029 is a prime.

It is a super-2 number, since 2×51666031² = 5338757518585922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51666037) 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, 164385 + ... + 164698.

It is an arithmetic number, because the mean of its divisors is an integer number (12998818).

Almost surely, 2^51666031 is an apocalyptic number.

51666031 is a deficient number, since it is larger than the sum of its proper divisors (329241).

51666031 is a wasteful number, since it uses less digits than its factorization.

51666031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329240.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 51666031 is about 7187.9086666429. The cubic root of 51666031 is about 372.4503328521.

The spelling of 51666031 in words is "fifty-one million, six hundred sixty-six thousand, thirty-one".