68537664 has 196 divisors, whose sum is σ = 221542356. Its totient is φ = 20901888.

The previous prime is 68537663. The next prime is 68537713. The reversal of 68537664 is 46673586.

It can be written as a sum of positive squares in 2 ways, for example, as 4665600 + 63872064 = 2160^2 + 7992^2 .

It is a super-2 number, since 2×68537664² = 9394822773153792, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68537663) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 606472 + ... + 606584.

Almost surely, 2^68537664 is an apocalyptic number.

68537664 is a gapful number since it is divisible by the number (64) 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 68537664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110771178).

68537664 is an abundant number, since it is smaller than the sum of its proper divisors (153004692).

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

68537664 is a wasteful number, since it uses less digits than its factorization.

68537664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 131 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 68537664 is about 8278.7477313903. The cubic root of 68537664 is about 409.2384515083.

The spelling of 68537664 in words is "sixty-eight million, five hundred thirty-seven thousand, six hundred sixty-four".