51551661 has 8 divisors (see below), whose sum is σ = 78554944. Its totient is φ = 29458080.

The previous prime is 51551657. The next prime is 51551683. The reversal of 51551661 is 16615515.

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

It is not a de Polignac number, because 51551661 - 2² = 51551657 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 (51551611) 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, 1227400 + ... + 1227441.

It is an arithmetic number, because the mean of its divisors is an integer number (9819368).

Almost surely, 2^51551661 is an apocalyptic number.

It is an amenable number.

51551661 is a deficient number, since it is larger than the sum of its proper divisors (27003283).

51551661 is a wasteful number, since it uses less digits than its factorization.

51551661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2454851.

The product of its digits is 4500, while the sum is 30.

The square root of 51551661 is about 7179.9485374200. The cubic root of 51551661 is about 372.1753061467.

The spelling of 51551661 in words is "fifty-one million, five hundred fifty-one thousand, six hundred sixty-one".