67640389 has 4 divisors (see below), whose sum is σ = 67861024. Its totient is φ = 67419756.

The previous prime is 67640381. The next prime is 67640393. The reversal of 67640389 is 98304676.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 67640389 - 2³ = 67640381 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 (67640381) 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, 109857 + ... + 110470.

It is an arithmetic number, because the mean of its divisors is an integer number (16965256).

Almost surely, 2^67640389 is an apocalyptic number.

It is an amenable number.

67640389 is a deficient number, since it is larger than the sum of its proper divisors (220635).

67640389 is a wasteful number, since it uses less digits than its factorization.

67640389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220634.

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 67640389 is about 8224.3777272205. The cubic root of 67640389 is about 407.4447243328. Note that the first 3 decimals are identical.

The spelling of 67640389 in words is "sixty-seven million, six hundred forty thousand, three hundred eighty-nine".