68381850561021 has 6 divisors (see below), whose sum is σ = 98773784143710. Its totient is φ = 45587900374008.

The previous prime is 68381850561001. The next prime is 68381850561041. The reversal of 68381850561021 is 12016505818386.

68381850561021 is a `hidden beast` number, since 6 + 8 + 3 + 8 + 1 + 8 + 50 + 561 + 0 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (68381850561001) and next prime (68381850561041).

It can be written as a sum of positive squares in only one way, i.e., 67956759600921 + 425090960100 = 8243589^2 + 651990^2 .

It is not a de Polignac number, because 68381850561021 - 2⁶ = 68381850560957 is a prime.

It is a super-2 number, since 2×68381850561021² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68381850561001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3798991697826 + ... + 3798991697843.

It is an arithmetic number, because the mean of its divisors is an integer number (16462297357285).

Almost surely, 2^{68381850561021} is an apocalyptic number.

It is an amenable number.

68381850561021 is a deficient number, since it is larger than the sum of its proper divisors (30391933582689).

68381850561021 is a wasteful number, since it uses less digits than its factorization.

68381850561021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7597983395675 (or 7597983395672 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 54.

The spelling of 68381850561021 in words is "sixty-eight trillion, three hundred eighty-one billion, eight hundred fifty million, five hundred sixty-one thousand, twenty-one".