61100085720 has 32 divisors (see below), whose sum is σ = 183300257520. Its totient is φ = 16293356160.

The previous prime is 61100085653. The next prime is 61100085731. The reversal of 61100085720 is 2758000116.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254583571 + ... + 254583810.

Almost surely, 2^61100085720 is an apocalyptic number.

61100085720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61100085720 is an abundant number, since it is smaller than the sum of its proper divisors (122200171800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61100085720 is a wasteful number, since it uses less digits than its factorization.

61100085720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509167395 (or 509167391 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 30.

Adding to 61100085720 its reverse (2758000116), we get a palindrome (63858085836).

The spelling of 61100085720 in words is "sixty-one billion, one hundred million, eighty-five thousand, seven hundred twenty".