67992640421 has 2 divisors, whose sum is σ = 67992640422. Its totient is φ = 67992640420.

The previous prime is 67992640351. The next prime is 67992640453. The reversal of 67992640421 is 12404629976.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64255152196 + 3737488225 = 253486^2 + 61135^2 .

It is a cyclic number.

It is not a de Polignac number, because 67992640421 - 2¹⁰ = 67992639397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67992640421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67992640021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33996320210 + 33996320211.

It is an arithmetic number, because the mean of its divisors is an integer number (33996320211).

Almost surely, 2^67992640421 is an apocalyptic number.

It is an amenable number.

67992640421 is a deficient number, since it is larger than the sum of its proper divisors (1).

67992640421 is an equidigital number, since it uses as much as digits as its factorization.

67992640421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1306368, while the sum is 50.

The spelling of 67992640421 in words is "sixty-seven billion, nine hundred ninety-two million, six hundred forty thousand, four hundred twenty-one".