68727981 has 32 divisors (see below), whose sum is σ = 108345600. Its totient is φ = 37933056.

The previous prime is 68727943. The next prime is 68727983. The reversal of 68727981 is 18972786.

It is not a de Polignac number, because 68727981 - 2⁶ = 68727917 is a prime.

It is a super-2 number, since 2×68727981² = 9447070744672722, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 68727981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68727983) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 152845 + ... + 153293.

It is an arithmetic number, because the mean of its divisors is an integer number (3385800).

Almost surely, 2^68727981 is an apocalyptic number.

It is an amenable number.

68727981 is a deficient number, since it is larger than the sum of its proper divisors (39617619).

68727981 is a wasteful number, since it uses less digits than its factorization.

68727981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693.

The product of its digits is 338688, while the sum is 48.

The square root of 68727981 is about 8290.2340738968. The cubic root of 68727981 is about 409.6168957575.

The spelling of 68727981 in words is "sixty-eight million, seven hundred twenty-seven thousand, nine hundred eighty-one".