51100561 has 2 divisors, whose sum is σ = 51100562. Its totient is φ = 51100560.

The previous prime is 51100547. The next prime is 51100571. The reversal of 51100561 is 16500115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50410000 + 690561 = 7100^2 + 831^2 .

It is a cyclic number.

It is not a de Polignac number, because 51100561 - 2⁵ = 51100529 is a prime.

It is a super-2 number, since 2×51100561² = 5222534669029442, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51100501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25550280 + 25550281.

It is an arithmetic number, because the mean of its divisors is an integer number (25550281).

Almost surely, 2^51100561 is an apocalyptic number.

It is an amenable number.

51100561 is a deficient number, since it is larger than the sum of its proper divisors (1).

51100561 is an equidigital number, since it uses as much as digits as its factorization.

51100561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 51100561 is about 7148.4656395621. The cubic root of 51100561 is about 371.0865576887.

Adding to 51100561 its reverse (16500115), we get a palindrome (67600676).

The spelling of 51100561 in words is "fifty-one million, one hundred thousand, five hundred sixty-one".