61699680 has 144 divisors (see below), whose sum is σ = 240668064. Its totient is φ = 14100480.

The previous prime is 61699667. The next prime is 61699691. The reversal of 61699680 is 8699616.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7020 + ... + 13140.

It is an arithmetic number, because the mean of its divisors is an integer number (1671306).

Almost surely, 2^61699680 is an apocalyptic number.

61699680 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 61699680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120334032).

61699680 is an abundant number, since it is smaller than the sum of its proper divisors (178968384).

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

61699680 is a wasteful number, since it uses less digits than its factorization.

61699680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6149 (or 6138 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 61699680 is about 7854.9143852750. The cubic root of 61699680 is about 395.1490758142.

The spelling of 61699680 in words is "sixty-one million, six hundred ninety-nine thousand, six hundred eighty".