67929821 has 2 divisors, whose sum is σ = 67929822. Its totient is φ = 67929820.

The previous prime is 67929811. The next prime is 67929847. The reversal of 67929821 is 12892976.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64224196 + 3705625 = 8014^2 + 1925^2 .

It is a cyclic number.

It is not a de Polignac number, because 67929821 - 2²⁶ = 820957 is a prime.

It is a super-2 number, since 2×67929821² = 9228921162184082, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67929811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33964910 + 33964911.

It is an arithmetic number, because the mean of its divisors is an integer number (33964911).

Almost surely, 2^67929821 is an apocalyptic number.

It is an amenable number.

67929821 is a deficient number, since it is larger than the sum of its proper divisors (1).

67929821 is an equidigital number, since it uses as much as digits as its factorization.

67929821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 67929821 is about 8241.9549258656. The cubic root of 67929821 is about 408.0250469213.

The spelling of 67929821 in words is "sixty-seven million, nine hundred twenty-nine thousand, eight hundred twenty-one".