64381820 has 24 divisors (see below), whose sum is σ = 135777600. Its totient is φ = 25643072.

The previous prime is 64381819. The next prime is 64381829. The reversal of 64381820 is 2818346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64381829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1955 + ... + 11514.

It is an arithmetic number, because the mean of its divisors is an integer number (5657400).

Almost surely, 2^64381820 is an apocalyptic number.

It is an amenable number.

64381820 is an abundant number, since it is smaller than the sum of its proper divisors (71395780).

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

64381820 is a wasteful number, since it uses less digits than its factorization.

64381820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13717 (or 13715 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 64381820 is about 8023.8282633666. The cubic root of 64381820 is about 400.7938816707.

The spelling of 64381820 in words is "sixty-four million, three hundred eighty-one thousand, eight hundred twenty".