78042749 has 4 divisors (see below), whose sum is σ = 81435936. Its totient is φ = 74649564.

The previous prime is 78042737. The next prime is 78042751. The reversal of 78042749 is 94724087.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78042749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78042049) 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, 1696559 + ... + 1696604.

It is an arithmetic number, because the mean of its divisors is an integer number (20358984).

Almost surely, 2^78042749 is an apocalyptic number.

It is an amenable number.

78042749 is a deficient number, since it is larger than the sum of its proper divisors (3393187).

78042749 is a wasteful number, since it uses less digits than its factorization.

78042749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3393186.

The product of its (nonzero) digits is 112896, while the sum is 41.

The square root of 78042749 is about 8834.1807203611. The cubic root of 78042749 is about 427.3439102757.

The spelling of 78042749 in words is "seventy-eight million, forty-two thousand, seven hundred forty-nine".