51661951 has 8 divisors (see below), whose sum is σ = 56697984. Its totient is φ = 46682520.

The previous prime is 51661921. The next prime is 51661999. The reversal of 51661951 is 15916615.

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 51661951 - 2¹¹ = 51659903 is a prime.

It is a super-2 number, since 2×51661951² = 5337914362252802, 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 (51661901) 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, 12225 + ... + 15898.

It is an arithmetic number, because the mean of its divisors is an integer number (7087248).

Almost surely, 2^51661951 is an apocalyptic number.

51661951 is a deficient number, since it is larger than the sum of its proper divisors (5036033).

51661951 is a wasteful number, since it uses less digits than its factorization.

51661951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28301.

The product of its digits is 8100, while the sum is 34.

The square root of 51661951 is about 7187.6248510895. The cubic root of 51661951 is about 372.4405286195.

It can be divided in two parts, 5166 and 1951, that added together give a palindrome (7117).

The spelling of 51661951 in words is "fifty-one million, six hundred sixty-one thousand, nine hundred fifty-one".