64990000 has 100 divisors (see below), whose sum is σ = 161342104. Its totient is φ = 25344000.

The previous prime is 64989989. The next prime is 64990021. The reversal of 64990000 is 9946.

It is a tau number, because it is divible by the number of its divisors (100).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 669952 + ... + 670048.

Almost surely, 2^64990000 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 64990000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80671052).

64990000 is an abundant number, since it is smaller than the sum of its proper divisors (96352104).

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

64990000 is an equidigital number, since it uses as much as digits as its factorization.

64990000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 64990000 is about 8061.6375507709. The cubic root of 64990000 is about 402.0519556950.

Adding to 64990000 its reverse (9946), we get a palindrome (64999946).

The spelling of 64990000 in words is "sixty-four million, nine hundred ninety thousand".