78261851 has 4 divisors (see below), whose sum is σ = 78359400. Its totient is φ = 78164304.

The previous prime is 78261839. The next prime is 78261857. The reversal of 78261851 is 15816287.

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

It is a cyclic number.

It is not a de Polignac number, because 78261851 - 2¹⁴ = 78245467 is a prime.

It is a super-2 number, since 2×78261851² = 12249834643892402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78261857) 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, 47561 + ... + 49178.

It is an arithmetic number, because the mean of its divisors is an integer number (19589850).

Almost surely, 2^78261851 is an apocalyptic number.

78261851 is a deficient number, since it is larger than the sum of its proper divisors (97549).

78261851 is an equidigital number, since it uses as much as digits as its factorization.

78261851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97548.

The product of its digits is 26880, while the sum is 38.

The square root of 78261851 is about 8846.5728392412. The cubic root of 78261851 is about 427.7434537754.

The spelling of 78261851 in words is "seventy-eight million, two hundred sixty-one thousand, eight hundred fifty-one".