78194561 has 4 divisors (see below), whose sum is σ = 79361712. Its totient is φ = 77027412.

The previous prime is 78194551. The next prime is 78194573. The reversal of 78194561 is 16549187.

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 not a de Polignac number, because 78194561 - 2¹⁸ = 77932417 is a prime.

It is a super-2 number, since 2×78194561² = 12228778739965442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78194551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 583475 + ... + 583608.

It is an arithmetic number, because the mean of its divisors is an integer number (19840428).

Almost surely, 2^78194561 is an apocalyptic number.

It is an amenable number.

78194561 is a deficient number, since it is larger than the sum of its proper divisors (1167151).

78194561 is a wasteful number, since it uses less digits than its factorization.

78194561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167150.

The product of its digits is 60480, while the sum is 41.

The square root of 78194561 is about 8842.7688537019. The cubic root of 78194561 is about 427.6208265106.

It can be divided in two parts, 78194 and 561, that multiplied together give a palindrome (43866834).

The spelling of 78194561 in words is "seventy-eight million, one hundred ninety-four thousand, five hundred sixty-one".