78291953 has 4 divisors (see below), whose sum is σ = 82897380. Its totient is φ = 73686528.

The previous prime is 78291943. The next prime is 78291959. The reversal of 78291953 is 35919287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 46403344 + 31888609 = 6812^2 + 5647^2 .

It is a cyclic number.

It is not a de Polignac number, because 78291953 - 2¹² = 78287857 is a prime.

It is a super-2 number, since 2×78291953² = 12259259809108418, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78291959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2302688 + ... + 2302721.

It is an arithmetic number, because the mean of its divisors is an integer number (20724345).

Almost surely, 2^78291953 is an apocalyptic number.

It is an amenable number.

78291953 is a deficient number, since it is larger than the sum of its proper divisors (4605427).

78291953 is a wasteful number, since it uses less digits than its factorization.

78291953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4605426.

The product of its digits is 136080, while the sum is 44.

The square root of 78291953 is about 8848.2740124840. The cubic root of 78291953 is about 427.7982879967.

The spelling of 78291953 in words is "seventy-eight million, two hundred ninety-one thousand, nine hundred fifty-three".