78270691 has 4 divisors (see below), whose sum is σ = 80795584. Its totient is φ = 75745800.

The previous prime is 78270677. The next prime is 78270697. The reversal of 78270691 is 19607287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19607287 = 7 ⋅2801041.

It is a cyclic number.

It is not a de Polignac number, because 78270691 - 2¹⁷ = 78139619 is a prime.

It is a super-2 number, since 2×78270691² = 12252602139234962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78270697) 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, 1262400 + ... + 1262461.

It is an arithmetic number, because the mean of its divisors is an integer number (20198896).

Almost surely, 2^78270691 is an apocalyptic number.

78270691 is a deficient number, since it is larger than the sum of its proper divisors (2524893).

78270691 is a wasteful number, since it uses less digits than its factorization.

78270691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2524892.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 78270691 is about 8847.0724536425. The cubic root of 78270691 is about 427.7595583003.

It can be divided in two parts, 78270 and 691, that added together give a square (78961 = 281²).

The spelling of 78270691 in words is "seventy-eight million, two hundred seventy thousand, six hundred ninety-one".