78217450 has 12 divisors (see below), whose sum is σ = 145484550. Its totient is φ = 31286960.

The previous prime is 78217441. The next prime is 78217481. The reversal of 78217450 is 5471287.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 75811849 + 2405601 = 8707^2 + 1551^2 .

It is a super-2 number, since 2×78217450² = 12235938969005000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 782125 + ... + 782224.

Almost surely, 2^78217450 is an apocalyptic number.

78217450 is a deficient number, since it is larger than the sum of its proper divisors (67267100).

78217450 is a wasteful number, since it uses less digits than its factorization.

78217450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1564361 (or 1564356 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 78217450 is about 8844.0629803275. The cubic root of 78217450 is about 427.6625466256.

The spelling of 78217450 in words is "seventy-eight million, two hundred seventeen thousand, four hundred fifty".