78549961 has 4 divisors (see below), whose sum is σ = 89771392. Its totient is φ = 67328532.

The previous prime is 78549959. The next prime is 78549967. The reversal of 78549961 is 16994587.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16994587 = 1009 ⋅16843.

It is a cyclic number.

It is not a de Polignac number, because 78549961 - 2¹ = 78549959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78549967) 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, 5610705 + ... + 5610718.

It is an arithmetic number, because the mean of its divisors is an integer number (22442848).

Almost surely, 2^78549961 is an apocalyptic number.

It is an amenable number.

78549961 is a deficient number, since it is larger than the sum of its proper divisors (11221431).

78549961 is a wasteful number, since it uses less digits than its factorization.

78549961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11221430.

The product of its digits is 544320, while the sum is 49.

The square root of 78549961 is about 8862.8415872112. The cubic root of 78549961 is about 428.2677034435.

The spelling of 78549961 in words is "seventy-eight million, five hundred forty-nine thousand, nine hundred sixty-one".