67721011 has 2 divisors, whose sum is σ = 67721012. Its totient is φ = 67721010.

The previous prime is 67720999. The next prime is 67721021. The reversal of 67721011 is 11012776.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67721011 is a prime.

It is a super-2 number, since 2×67721011² = 9172270661724242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (67721021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33860505 + 33860506.

It is an arithmetic number, because the mean of its divisors is an integer number (33860506).

Almost surely, 2^67721011 is an apocalyptic number.

67721011 is a deficient number, since it is larger than the sum of its proper divisors (1).

67721011 is an equidigital number, since it uses as much as digits as its factorization.

67721011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 588, while the sum is 25.

The square root of 67721011 is about 8229.2776718252. The cubic root of 67721011 is about 407.6065406999.

Adding to 67721011 its reverse (11012776), we get a palindrome (78733787).

The spelling of 67721011 in words is "sixty-seven million, seven hundred twenty-one thousand, eleven".