68221656 has 64 divisors (see below), whose sum is σ = 191030400. Its totient is φ = 22557600.

The previous prime is 68221651. The next prime is 68221679. The reversal of 68221656 is 65612286.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 68221656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68221651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27091 + ... + 29501.

It is an arithmetic number, because the mean of its divisors is an integer number (2984850).

Almost surely, 2^68221656 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 68221656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95515200).

68221656 is an abundant number, since it is smaller than the sum of its proper divisors (122808744).

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

68221656 is a wasteful number, since it uses less digits than its factorization.

68221656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2557 (or 2547 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 68221656 is about 8259.6401858677. The cubic root of 68221656 is about 408.6085210218.

The spelling of 68221656 in words is "sixty-eight million, two hundred twenty-one thousand, six hundred fifty-six".