68619991 has 8 divisors (see below), whose sum is σ = 75398400. Its totient is φ = 61931640.

The previous prime is 68619977. The next prime is 68620033. The reversal of 68619991 is 19991686.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 68619991 - 2¹³ = 68611799 is a prime.

It is a super-3 number, since 3×68619991³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68619911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20911 + ... + 23968.

It is an arithmetic number, because the mean of its divisors is an integer number (9424800).

Almost surely, 2^68619991 is an apocalyptic number.

68619991 is a deficient number, since it is larger than the sum of its proper divisors (6778409).

68619991 is a wasteful number, since it uses less digits than its factorization.

68619991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45029.

The product of its digits is 209952, while the sum is 49.

The square root of 68619991 is about 8283.7184283388. The cubic root of 68619991 is about 409.4022441399.

The spelling of 68619991 in words is "sixty-eight million, six hundred nineteen thousand, nine hundred ninety-one".