61512780 has 96 divisors (see below), whose sum is σ = 198245376. Its totient is φ = 13959936.

The previous prime is 61512779. The next prime is 61512809. The reversal of 61512780 is 8721516.

61512780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69702 + ... + 70578.

It is an arithmetic number, because the mean of its divisors is an integer number (2065056).

Almost surely, 2^61512780 is an apocalyptic number.

61512780 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 61512780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99122688).

61512780 is an abundant number, since it is smaller than the sum of its proper divisors (136732596).

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

61512780 is a wasteful number, since it uses less digits than its factorization.

61512780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1061 counting only the distinct ones).

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

The square root of 61512780 is about 7843.0083513917. The cubic root of 61512780 is about 394.7496784972.

The spelling of 61512780 in words is "sixty-one million, five hundred twelve thousand, seven hundred eighty".