64161720 has 384 divisors, whose sum is σ = 264176640. Its totient is φ = 13685760.

The previous prime is 64161709. The next prime is 64161781. The reversal of 64161720 is 2716146.

64161720 is a `hidden beast` number, since 6 + 41 + 617 + 2 + 0 = 666.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1564900 + ... + 1564940.

It is an arithmetic number, because the mean of its divisors is an integer number (687960).

Almost surely, 2^64161720 is an apocalyptic number.

64161720 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 64161720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132088320).

64161720 is an abundant number, since it is smaller than the sum of its proper divisors (200014920).

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

64161720 is a wasteful number, since it uses less digits than its factorization.

64161720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 64161720 is about 8010.1011229572. The cubic root of 64161720 is about 400.3366332823.

Adding to 64161720 its reverse (2716146), we get a palindrome (66877866).

The spelling of 64161720 in words is "sixty-four million, one hundred sixty-one thousand, seven hundred twenty".