67638989 has 4 divisors (see below), whose sum is σ = 73788000. Its totient is φ = 61489980.

The previous prime is 67638983. The next prime is 67639001. The reversal of 67638989 is 98983676.

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 67638989 - 2¹² = 67634893 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67638983) 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, 3074489 + ... + 3074510.

It is an arithmetic number, because the mean of its divisors is an integer number (18447000).

Almost surely, 2^67638989 is an apocalyptic number.

It is an amenable number.

67638989 is a deficient number, since it is larger than the sum of its proper divisors (6149011).

67638989 is a wasteful number, since it uses less digits than its factorization.

67638989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6149010.

The product of its digits is 3919104, while the sum is 56.

The square root of 67638989 is about 8224.2926139577. The cubic root of 67638989 is about 407.4419132581.

The spelling of 67638989 in words is "sixty-seven million, six hundred thirty-eight thousand, nine hundred eighty-nine".