71267821 has 2 divisors, whose sum is σ = 71267822. Its totient is φ = 71267820.

The previous prime is 71267771. The next prime is 71267831. The reversal of 71267821 is 12876217.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43705321 + 27562500 = 6611^2 + 5250^2 .

It is a cyclic number.

It is not a de Polignac number, because 71267821 - 2¹¹ = 71265773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71267831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35633910 + 35633911.

It is an arithmetic number, because the mean of its divisors is an integer number (35633911).

Almost surely, 2^71267821 is an apocalyptic number.

It is an amenable number.

71267821 is a deficient number, since it is larger than the sum of its proper divisors (1).

71267821 is an equidigital number, since it uses as much as digits as its factorization.

71267821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 34.

The square root of 71267821 is about 8442.0270670023. The cubic root of 71267821 is about 414.6017779650.

The spelling of 71267821 in words is "seventy-one million, two hundred sixty-seven thousand, eight hundred twenty-one".