68140405 has 4 divisors (see below), whose sum is σ = 81768492. Its totient is φ = 54512320.

The previous prime is 68140399. The next prime is 68140409. The reversal of 68140405 is 50404186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15476356 + 52664049 = 3934^2 + 7257^2 .

It is a de Polignac number, because none of the positive numbers 2^k-68140405 is a prime.

It is a super-2 number, since 2×68140405² = 9286229587128050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68140409) 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, 6814036 + ... + 6814045.

It is an arithmetic number, because the mean of its divisors is an integer number (20442123).

Almost surely, 2^68140405 is an apocalyptic number.

It is an amenable number.

68140405 is a deficient number, since it is larger than the sum of its proper divisors (13628087).

68140405 is a wasteful number, since it uses less digits than its factorization.

68140405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13628086.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 68140405 is about 8254.7201648511. The cubic root of 68140405 is about 408.4462409786.

The spelling of 68140405 in words is "sixty-eight million, one hundred forty thousand, four hundred five".