64737990 has 48 divisors (see below), whose sum is σ = 169236288. Its totient is φ = 17169408.

The previous prime is 64737979. The next prime is 64737991. The reversal of 64737990 is 9973746.

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 (64737991) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15507 + ... + 19233.

It is an arithmetic number, because the mean of its divisors is an integer number (3525756).

Almost surely, 2^64737990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64737990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84618144).

64737990 is an abundant number, since it is smaller than the sum of its proper divisors (104498298).

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

64737990 is a wasteful number, since it uses less digits than its factorization.

64737990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3933 (or 3930 counting only the distinct ones).

The product of its (nonzero) digits is 285768, while the sum is 45.

The square root of 64737990 is about 8045.9921700186. The cubic root of 64737990 is about 401.5316071305.

The spelling of 64737990 in words is "sixty-four million, seven hundred thirty-seven thousand, nine hundred ninety".