61720398 has 48 divisors (see below), whose sum is σ = 141523200. Its totient is φ = 19386000.

The previous prime is 61720397. The next prime is 61720423. The reversal of 61720398 is 89302716.

61720398 is a `hidden beast` number, since 617 + 2 + 0 + 39 + 8 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61720397) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85483 + ... + 86201.

It is an arithmetic number, because the mean of its divisors is an integer number (2948400).

Almost surely, 2^61720398 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61720398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70761600).

61720398 is an abundant number, since it is smaller than the sum of its proper divisors (79802802).

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

61720398 is a wasteful number, since it uses less digits than its factorization.

61720398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997 (or 994 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 61720398 is about 7856.2330668075. The cubic root of 61720398 is about 395.1932996113.

The spelling of 61720398 in words is "sixty-one million, seven hundred twenty thousand, three hundred ninety-eight".