64131984 has 180 divisors, whose sum is σ = 213630300. Its totient is φ = 17902080.

The previous prime is 64131983. The next prime is 64132031. The reversal of 64131984 is 48913146.

64131984 is a `hidden beast` number, since 641 + 3 + 1 + 9 + 8 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4410000 + 59721984 = 2100^2 + 7728^2 .

It is a super-2 number, since 2×64131984² = 8225822743552512, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is a zygodrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64131983) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 430342 + ... + 430490.

It is an arithmetic number, because the mean of its divisors is an integer number (1186835).

Almost surely, 2^64131984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64131984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106815150).

64131984 is an abundant number, since it is smaller than the sum of its proper divisors (149498316).

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

64131984 is a wasteful number, since it uses less digits than its factorization.

64131984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238 (or 222 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 64131984 is about 8008.2447515045. The cubic root of 64131984 is about 400.2747778663.

The spelling of 64131984 in words is "sixty-four million, one hundred thirty-one thousand, nine hundred eighty-four".