68561091 has 12 divisors (see below), whose sum is σ = 103338768. Its totient is φ = 43719984.

The previous prime is 68561083. The next prime is 68561093. The reversal of 68561091 is 19016586.

68561091 is a `hidden beast` number, since 6 + 8 + 561 + 0 + 91 = 666.

It is not a de Polignac number, because 68561091 - 2³ = 68561083 is a prime.

It is a super-2 number, since 2×68561091² = 9401246398220562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (68561093) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165400 + ... + 165813.

It is an arithmetic number, because the mean of its divisors is an integer number (8611564).

Almost surely, 2^68561091 is an apocalyptic number.

68561091 is a deficient number, since it is larger than the sum of its proper divisors (34777677).

68561091 is a wasteful number, since it uses less digits than its factorization.

68561091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331242 (or 331239 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 68561091 is about 8280.1624984055. The cubic root of 68561091 is about 409.2850737425.

It can be divided in two parts, 685 and 61091, that added together give a triangular number (61776 = T₃₅₁).

The spelling of 68561091 in words is "sixty-eight million, five hundred sixty-one thousand, ninety-one".