67540664621 has 2 divisors, whose sum is σ = 67540664622. Its totient is φ = 67540664620.

The previous prime is 67540664501. The next prime is 67540664677. The reversal of 67540664621 is 12646604576.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52939567396 + 14601097225 = 230086^2 + 120835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67540664621 is a prime.

It is a super-3 number, since 3×67540664621³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67540064621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33770332310 + 33770332311.

It is an arithmetic number, because the mean of its divisors is an integer number (33770332311).

Almost surely, 2^67540664621 is an apocalyptic number.

It is an amenable number.

67540664621 is a deficient number, since it is larger than the sum of its proper divisors (1).

67540664621 is an equidigital number, since it uses as much as digits as its factorization.

67540664621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1451520, while the sum is 47.

The spelling of 67540664621 in words is "sixty-seven billion, five hundred forty million, six hundred sixty-four thousand, six hundred twenty-one".