61720649500 has 96 divisors (see below), whose sum is σ = 141976074240. Its totient is φ = 23393691200.

The previous prime is 61720649491. The next prime is 61720649509. The reversal of 61720649500 is 594602716.

It is an interprime number because it is at equal distance from previous prime (61720649491) and next prime (61720649509).

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61720649509) 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, 1205421 + ... + 1255579.

It is an arithmetic number, because the mean of its divisors is an integer number (1478917440).

Almost surely, 2^61720649500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61720649500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70988037120).

61720649500 is an abundant number, since it is smaller than the sum of its proper divisors (80255424740).

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

61720649500 is a wasteful number, since it uses less digits than its factorization.

61720649500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50308 (or 50296 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 61720649500 in words is "sixty-one billion, seven hundred twenty million, six hundred forty-nine thousand, five hundred".