61662720 has 320 divisors, whose sum is σ = 238841856. Its totient is φ = 13271040.

The previous prime is 61662703. The next prime is 61662721. The reversal of 61662720 is 2726616.

It is a tau number, because it is divible by the number of its divisors (320).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61662721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1666542 + ... + 1666578.

Almost surely, 2^61662720 is an apocalyptic number.

61662720 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 61662720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119420928).

61662720 is an abundant number, since it is smaller than the sum of its proper divisors (177179136).

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

61662720 is a wasteful number, since it uses less digits than its factorization.

61662720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 61662720 is about 7852.5613655673. The cubic root of 61662720 is about 395.0701579168.

It can be divided in two parts, 616 and 62720, that added together give a palindrome (63336).

The spelling of 61662720 in words is "sixty-one million, six hundred sixty-two thousand, seven hundred twenty".