61801099551 has 8 divisors (see below), whose sum is σ = 91557184560. Its totient is φ = 41200733016.

The previous prime is 61801099523. The next prime is 61801099603. The reversal of 61801099551 is 15599010816.

61801099551 is a `hidden beast` number, since 6 + 1 + 8 + 0 + 1 + 0 + 99 + 551 = 666.

It is not a de Polignac number, because 61801099551 - 2⁶ = 61801099487 is a prime.

It is a super-2 number, since 2×61801099551² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61801099497 and 61801099506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61801099501) 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, 1144464780 + ... + 1144464833.

It is an arithmetic number, because the mean of its divisors is an integer number (11444648070).

Almost surely, 2^61801099551 is an apocalyptic number.

61801099551 is a deficient number, since it is larger than the sum of its proper divisors (29756085009).

61801099551 is a wasteful number, since it uses less digits than its factorization.

61801099551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2288929622 (or 2288929616 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 45.

The spelling of 61801099551 in words is "sixty-one billion, eight hundred one million, ninety-nine thousand, five hundred fifty-one".