78215833 has 2 divisors, whose sum is σ = 78215834. Its totient is φ = 78215832.

The previous prime is 78215791. The next prime is 78215843. The reversal of 78215833 is 33851287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74183769 + 4032064 = 8613^2 + 2008^2 .

It is a cyclic number.

It is not a de Polignac number, because 78215833 - 2¹³ = 78207641 is a prime.

It is a super-2 number, since 2×78215833² = 12235433063767778, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78215792 and 78215801.

It is not a weakly prime, because it can be changed into another prime (78215843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39107916 + 39107917.

It is an arithmetic number, because the mean of its divisors is an integer number (39107917).

Almost surely, 2^78215833 is an apocalyptic number.

It is an amenable number.

78215833 is a deficient number, since it is larger than the sum of its proper divisors (1).

78215833 is an equidigital number, since it uses as much as digits as its factorization.

78215833 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 37.

The square root of 78215833 is about 8843.9715625956. The cubic root of 78215833 is about 427.6595995633.

The spelling of 78215833 in words is "seventy-eight million, two hundred fifteen thousand, eight hundred thirty-three".