78332021 has 2 divisors, whose sum is σ = 78332022. Its totient is φ = 78332020.

The previous prime is 78331973. The next prime is 78332027. The reversal of 78332021 is 12023387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51696100 + 26635921 = 7190^2 + 5161^2 .

It is an emirp because it is prime and its reverse (12023387) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78332021 - 2¹⁸ = 78069877 is a prime.

It is a super-2 number, since 2×78332021² = 12271811027888882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78332027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39166010 + 39166011.

It is an arithmetic number, because the mean of its divisors is an integer number (39166011).

Almost surely, 2^78332021 is an apocalyptic number.

It is an amenable number.

78332021 is a deficient number, since it is larger than the sum of its proper divisors (1).

78332021 is an equidigital number, since it uses as much as digits as its factorization.

78332021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 78332021 is about 8850.5378932582. The cubic root of 78332021 is about 427.8712546208.

The spelling of 78332021 in words is "seventy-eight million, three hundred thirty-two thousand, twenty-one".