78071690 has 16 divisors (see below), whose sum is σ = 142109640. Its totient is φ = 30877440.

The previous prime is 78071657. The next prime is 78071723. The reversal of 78071690 is 9617087.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78071657) and next prime (78071723).

It can be written as a sum of positive squares in 4 ways, for example, as 43414921 + 34656769 = 6589^2 + 5887^2 .

It is a super-2 number, since 2×78071690² = 12190377558912200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42971 + ... + 44750.

Almost surely, 2^78071690 is an apocalyptic number.

78071690 is a deficient number, since it is larger than the sum of its proper divisors (64037950).

78071690 is a wasteful number, since it uses less digits than its factorization.

78071690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87817.

The product of its (nonzero) digits is 21168, while the sum is 38.

The square root of 78071690 is about 8835.8185812068. The cubic root of 78071690 is about 427.3967284716.

The spelling of 78071690 in words is "seventy-eight million, seventy-one thousand, six hundred ninety".