61620133181 has 2 divisors, whose sum is σ = 61620133182. Its totient is φ = 61620133180.

The previous prime is 61620133151. The next prime is 61620133187. The reversal of 61620133181 is 18133102616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56469917956 + 5150215225 = 237634^2 + 71765^2 .

It is a cyclic number.

It is not a de Polignac number, because 61620133181 - 2²² = 61615938877 is a prime.

It is a super-2 number, since 2×61620133181² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61620133187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30810066590 + 30810066591.

It is an arithmetic number, because the mean of its divisors is an integer number (30810066591).

Almost surely, 2^61620133181 is an apocalyptic number.

It is an amenable number.

61620133181 is a deficient number, since it is larger than the sum of its proper divisors (1).

61620133181 is an equidigital number, since it uses as much as digits as its factorization.

61620133181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

Adding to 61620133181 its reverse (18133102616), we get a palindrome (79753235797).

The spelling of 61620133181 in words is "sixty-one billion, six hundred twenty million, one hundred thirty-three thousand, one hundred eighty-one".