67387921 has 2 divisors, whose sum is σ = 67387922. Its totient is φ = 67387920.

The previous prime is 67387891. The next prime is 67388023. The reversal of 67387921 is 12978376.

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., 46730896 + 20657025 = 6836^2 + 4545^2 .

It is a cyclic number.

It is not a de Polignac number, because 67387921 - 2⁹ = 67387409 is a prime.

It is a super-2 number, since 2×67387921² = 9082263793404482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (67387121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33693960 + 33693961.

It is an arithmetic number, because the mean of its divisors is an integer number (33693961).

Almost surely, 2^67387921 is an apocalyptic number.

It is an amenable number.

67387921 is a deficient number, since it is larger than the sum of its proper divisors (1).

67387921 is an equidigital number, since it uses as much as digits as its factorization.

67387921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 67387921 is about 8209.0146180891. The cubic root of 67387921 is about 406.9371626735.

The spelling of 67387921 in words is "sixty-seven million, three hundred eighty-seven thousand, nine hundred twenty-one".