64288890 has 80 divisors (see below), whose sum is σ = 174414240. Its totient is φ = 16990560.

The previous prime is 64288877. The next prime is 64288891. The reversal of 64288890 is 9888246.

It is a happy number.

It is a super-2 number, since 2×64288890² = 8266122754864200, which contains 22 as substring.

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 Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64288891) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 112305 + ... + 112875.

It is an arithmetic number, because the mean of its divisors is an integer number (2180178).

Almost surely, 2^64288890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64288890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87207120).

64288890 is an abundant number, since it is smaller than the sum of its proper divisors (110125350).

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

64288890 is a wasteful number, since it uses less digits than its factorization.

64288890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729 (or 720 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 64288890 is about 8018.0352955072. The cubic root of 64288890 is about 400.6009508597.

The spelling of 64288890 in words is "sixty-four million, two hundred eighty-eight thousand, eight hundred ninety".