78022621 has 2 divisors, whose sum is σ = 78022622. Its totient is φ = 78022620.

The previous prime is 78022589. The next prime is 78022627. The reversal of 78022621 is 12622087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75446596 + 2576025 = 8686^2 + 1605^2 .

It is a cyclic number.

It is not a de Polignac number, because 78022621 - 2⁵ = 78022589 is a prime.

It is a super-3 number, since 3×78022621³ (a number of 25 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78022621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78022627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39011310 + 39011311.

It is an arithmetic number, because the mean of its divisors is an integer number (39011311).

Almost surely, 2^78022621 is an apocalyptic number.

It is an amenable number.

78022621 is a deficient number, since it is larger than the sum of its proper divisors (1).

78022621 is an equidigital number, since it uses as much as digits as its factorization.

78022621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 78022621 is about 8833.0414354287. The cubic root of 78022621 is about 427.3071683707.

The spelling of 78022621 in words is "seventy-eight million, twenty-two thousand, six hundred twenty-one".