64496640 has 352 divisors, whose sum is σ = 247605120. Its totient is φ = 14155776.

The previous prime is 64496639. The next prime is 64496651. The reversal of 64496640 is 4669446.

64496640 = 383² + 384² + ... + 629².

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3394551 + ... + 3394569.

Almost surely, 2^64496640 is an apocalyptic number.

64496640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64496640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123802560).

64496640 is an abundant number, since it is smaller than the sum of its proper divisors (183108480).

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

64496640 is a wasteful number, since it uses less digits than its factorization.

64496640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 39.

The square root of 64496640 is about 8030.9800149172. The cubic root of 64496640 is about 401.0320018075.

The spelling of 64496640 in words is "sixty-four million, four hundred ninety-six thousand, six hundred forty".