78210749 has 2 divisors, whose sum is σ = 78210750. Its totient is φ = 78210748.

The previous prime is 78210731. The next prime is 78210751. The reversal of 78210749 is 94701287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78198649 + 12100 = 8843^2 + 110^2 .

It is a cyclic number.

It is not a de Polignac number, because 78210749 - 2¹⁶ = 78145213 is a prime.

It is a super-2 number, since 2×78210749² = 12233842518282002, which contains 22 as substring.

Together with 78210751, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78210719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39105374 + 39105375.

It is an arithmetic number, because the mean of its divisors is an integer number (39105375).

Almost surely, 2^78210749 is an apocalyptic number.

It is an amenable number.

78210749 is a deficient number, since it is larger than the sum of its proper divisors (1).

78210749 is an equidigital number, since it uses as much as digits as its factorization.

78210749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 78210749 is about 8843.6841304967. The cubic root of 78210749 is about 427.6503334577.

The spelling of 78210749 in words is "seventy-eight million, two hundred ten thousand, seven hundred forty-nine".