61156699980 has 96 divisors (see below), whose sum is σ = 182171566080. Its totient is φ = 15276334080.

The previous prime is 61156699937. The next prime is 61156699987. The reversal of 61156699980 is 8999665116.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is not an unprimeable number, because it can be changed into a prime (61156699987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73141 + ... + 357299.

It is an arithmetic number, because the mean of its divisors is an integer number (1897620480).

Almost surely, 2^61156699980 is an apocalyptic number.

61156699980 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61156699980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91085783040).

61156699980 is an abundant number, since it is smaller than the sum of its proper divisors (121014866100).

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

61156699980 is a wasteful number, since it uses less digits than its factorization.

61156699980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284399 (or 284397 counting only the distinct ones).

The product of its (nonzero) digits is 6298560, while the sum is 60.

The spelling of 61156699980 in words is "sixty-one billion, one hundred fifty-six million, six hundred ninety-nine thousand, nine hundred eighty".