68191961 has 4 divisors (see below), whose sum is σ = 69309924. Its totient is φ = 67074000.

The previous prime is 68191951. The next prime is 68191993. The reversal of 68191961 is 16919186.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16919186 = 2 ⋅8459593.

It can be written as a sum of positive squares in 2 ways, for example, as 5148361 + 63043600 = 2269^2 + 7940^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68191961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68191901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 558890 + ... + 559011.

It is an arithmetic number, because the mean of its divisors is an integer number (17327481).

Almost surely, 2^68191961 is an apocalyptic number.

68191961 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

68191961 is a deficient number, since it is larger than the sum of its proper divisors (1117963).

68191961 is a wasteful number, since it uses less digits than its factorization.

68191961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117962.

The product of its digits is 23328, while the sum is 41.

The square root of 68191961 is about 8257.8423937491. The cubic root of 68191961 is about 408.5492270886.

The spelling of 68191961 in words is "sixty-eight million, one hundred ninety-one thousand, nine hundred sixty-one".