51636661 has 8 divisors (see below), whose sum is σ = 54457920. Its totient is φ = 48825792.

The previous prime is 51636649. The next prime is 51636677. The reversal of 51636661 is 16663615.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51636661 - 2²¹ = 49539509 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 (51636601) 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, 8976 + ... + 13558.

It is an arithmetic number, because the mean of its divisors is an integer number (6807240).

Almost surely, 2^51636661 is an apocalyptic number.

It is an amenable number.

51636661 is a deficient number, since it is larger than the sum of its proper divisors (2821259).

51636661 is a wasteful number, since it uses less digits than its factorization.

51636661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5195.

The product of its digits is 19440, while the sum is 34.

The square root of 51636661 is about 7185.8653619449. The cubic root of 51636661 is about 372.3797452760.

It can be divided in two parts, 51 and 636661, that multiplied together give a triangular number (32469711 = T₈₀₅₈).

The spelling of 51636661 in words is "fifty-one million, six hundred thirty-six thousand, six hundred sixty-one".