51661101 has 4 divisors (see below), whose sum is σ = 68881472. Its totient is φ = 34440732.

The previous prime is 51661073. The next prime is 51661117. The reversal of 51661101 is 10116615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 51661101 - 2⁹ = 51660589 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 (51661501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8610181 + ... + 8610186.

It is an arithmetic number, because the mean of its divisors is an integer number (17220368).

Almost surely, 2^51661101 is an apocalyptic number.

It is an amenable number.

51661101 is a deficient number, since it is larger than the sum of its proper divisors (17220371).

51661101 is a wasteful number, since it uses less digits than its factorization.

51661101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17220370.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 51661101 is about 7187.5657214387. The cubic root of 51661101 is about 372.4384860061.

Adding to 51661101 its reverse (10116615), we get a palindrome (61777716).

The spelling of 51661101 in words is "fifty-one million, six hundred sixty-one thousand, one hundred one".