78279401 has 2 divisors, whose sum is σ = 78279402. Its totient is φ = 78279400.

The previous prime is 78279389. The next prime is 78279403. The reversal of 78279401 is 10497287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59660176 + 18619225 = 7724^2 + 4315^2 .

It is a cyclic number.

It is not a de Polignac number, because 78279401 - 2⁶ = 78279337 is a prime.

It is a super-2 number, since 2×78279401² = 12255329241837602, which contains 22 as substring.

Together with 78279403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78279403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39139700 + 39139701.

It is an arithmetic number, because the mean of its divisors is an integer number (39139701).

Almost surely, 2^78279401 is an apocalyptic number.

It is an amenable number.

78279401 is a deficient number, since it is larger than the sum of its proper divisors (1).

78279401 is an equidigital number, since it uses as much as digits as its factorization.

78279401 is an evil number, because the sum of its binary digits is even.

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

The square root of 78279401 is about 8847.5646931797. The cubic root of 78279401 is about 427.7754248079.

The spelling of 78279401 in words is "seventy-eight million, two hundred seventy-nine thousand, four hundred one".