64155780 has 288 divisors, whose sum is σ = 233654400. Its totient is φ = 14556672.

The previous prime is 64155779. The next prime is 64155787. The reversal of 64155780 is 8755146.

64155780 is a `hidden beast` number, since 641 + 5 + 5 + 7 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64155787) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1733922 + ... + 1733958.

It is an arithmetic number, because the mean of its divisors is an integer number (811300).

Almost surely, 2^64155780 is an apocalyptic number.

64155780 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 64155780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116827200).

64155780 is an abundant number, since it is smaller than the sum of its proper divisors (169498620).

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

64155780 is a wasteful number, since it uses less digits than its factorization.

64155780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 64155780 is about 8009.7303325393. The cubic root of 64155780 is about 400.3242787039.

The spelling of 64155780 in words is "sixty-four million, one hundred fifty-five thousand, seven hundred eighty".