64857780 has 96 divisors (see below), whose sum is σ = 217324800. Its totient is φ = 15963264.

The previous prime is 64857739. The next prime is 64857787. The reversal of 64857780 is 8775846.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64857787) 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, 2401 + ... + 11639.

It is an arithmetic number, because the mean of its divisors is an integer number (2263800).

Almost surely, 2^64857780 is an apocalyptic number.

64857780 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 64857780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108662400).

64857780 is an abundant number, since it is smaller than the sum of its proper divisors (152467020).

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

64857780 is a wasteful number, since it uses less digits than its factorization.

64857780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9270 (or 9262 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The square root of 64857780 is about 8053.4328084364. The cubic root of 64857780 is about 401.7791167933.

The spelling of 64857780 in words is "sixty-four million, eight hundred fifty-seven thousand, seven hundred eighty".