78287161 has 2 divisors, whose sum is σ = 78287162. Its totient is φ = 78287160.

The previous prime is 78287137. The next prime is 78287173. The reversal of 78287161 is 16178287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74287161 + 4000000 = 8619^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 78287161 - 2⁵ = 78287129 is a prime.

It is a super-2 number, since 2×78287161² = 12257759154879842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78287861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39143580 + 39143581.

It is an arithmetic number, because the mean of its divisors is an integer number (39143581).

Almost surely, 2^78287161 is an apocalyptic number.

It is an amenable number.

78287161 is a deficient number, since it is larger than the sum of its proper divisors (1).

78287161 is an equidigital number, since it uses as much as digits as its factorization.

78287161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37632, while the sum is 40.

The square root of 78287161 is about 8848.0032210663. The cubic root of 78287161 is about 427.7895597637.

The spelling of 78287161 in words is "seventy-eight million, two hundred eighty-seven thousand, one hundred sixty-one".