67921789 has 24 divisors (see below), whose sum is σ = 79305912. Its totient is φ = 57784320.

The previous prime is 67921747. The next prime is 67921801. The reversal of 67921789 is 98712976.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1172889 + 66748900 = 1083^2 + 8170^2 .

It is not a de Polignac number, because 67921789 - 2¹¹ = 67919741 is a prime.

It is a super-2 number, since 2×67921789² = 9226738841921042, 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 (67921709) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 192237 + ... + 192589.

It is an arithmetic number, because the mean of its divisors is an integer number (3304413).

Almost surely, 2^67921789 is an apocalyptic number.

It is an amenable number.

67921789 is a deficient number, since it is larger than the sum of its proper divisors (11384123).

67921789 is a wasteful number, since it uses less digits than its factorization.

67921789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445 (or 426 counting only the distinct ones).

The product of its digits is 381024, while the sum is 49.

The square root of 67921789 is about 8241.4676484228. The cubic root of 67921789 is about 408.0089647043.

The spelling of 67921789 in words is "sixty-seven million, nine hundred twenty-one thousand, seven hundred eighty-nine".