67139407 has 4 divisors (see below), whose sum is σ = 70673080. Its totient is φ = 63605736.

The previous prime is 67139399. The next prime is 67139411. The reversal of 67139407 is 70493176.

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

It is a cyclic number.

It is not a de Polignac number, because 67139407 - 2³ = 67139399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67139207) 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, 1766808 + ... + 1766845.

It is an arithmetic number, because the mean of its divisors is an integer number (17668270).

Almost surely, 2^67139407 is an apocalyptic number.

67139407 is a deficient number, since it is larger than the sum of its proper divisors (3533673).

67139407 is a wasteful number, since it uses less digits than its factorization.

67139407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3533672.

The product of its (nonzero) digits is 31752, while the sum is 37.

The square root of 67139407 is about 8193.8639847144. The cubic root of 67139407 is about 406.4363105351.

The spelling of 67139407 in words is "sixty-seven million, one hundred thirty-nine thousand, four hundred seven".