67687821 has 12 divisors (see below), whose sum is σ = 98270172. Its totient is φ = 44894976.

The previous prime is 67687819. The next prime is 67687847. The reversal of 67687821 is 12878676.

It can be written as a sum of positive squares in 2 ways, for example, as 35640900 + 32046921 = 5970^2 + 5661^2 .

It is not a de Polignac number, because 67687821 - 2¹ = 67687819 is a prime.

It is a super-2 number, since 2×67687821² = 9163282223456082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67687811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17316 + ... + 20861.

It is an arithmetic number, because the mean of its divisors is an integer number (8189181).

Almost surely, 2^67687821 is an apocalyptic number.

It is an amenable number.

67687821 is a deficient number, since it is larger than the sum of its proper divisors (30582351).

67687821 is a wasteful number, since it uses less digits than its factorization.

67687821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38380 (or 38377 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 67687821 is about 8227.2608442908. The cubic root of 67687821 is about 407.5399406320.

The spelling of 67687821 in words is "sixty-seven million, six hundred eighty-seven thousand, eight hundred twenty-one".