78212945 has 8 divisors (see below), whose sum is σ = 93932136. Its totient is φ = 62519296.

The previous prime is 78212941. The next prime is 78212951. The reversal of 78212945 is 54921287.

It can be written as a sum of positive squares in 4 ways, for example, as 39287824 + 38925121 = 6268^2 + 6239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78212945 - 2² = 78212941 is a prime.

It is a super-2 number, since 2×78212945² = 12234529531146050, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78212899 and 78212908.

It is not an unprimeable number, because it can be changed into a prime (78212941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1169 + ... + 12561.

It is an arithmetic number, because the mean of its divisors is an integer number (11741517).

Almost surely, 2^78212945 is an apocalyptic number.

It is an amenable number.

78212945 is a deficient number, since it is larger than the sum of its proper divisors (15719191).

78212945 is a wasteful number, since it uses less digits than its factorization.

78212945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12771.

The product of its digits is 40320, while the sum is 38.

The square root of 78212945 is about 8843.8082860270. The cubic root of 78212945 is about 427.6543359396.

The spelling of 78212945 in words is "seventy-eight million, two hundred twelve thousand, nine hundred forty-five".