161226778 has 8 divisors (see below), whose sum is σ = 245153268. Its totient is φ = 79509024.

The previous prime is 161226743. The next prime is 161226787. The reversal of 161226778 is 877622161.

It can be written as a sum of positive squares in 2 ways, for example, as 154430329 + 6796449 = 12427^2 + 2607^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161226778² = 51988147888522568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161226778.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 552001 + ... + 552292.

Almost surely, 2^161226778 is an apocalyptic number.

161226778 is a deficient number, since it is larger than the sum of its proper divisors (83926490).

161226778 is a wasteful number, since it uses less digits than its factorization.

161226778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1104368.

The product of its digits is 56448, while the sum is 40.

The square root of 161226778 is about 12697.5107009209. The cubic root of 161226778 is about 544.2674871282.

The spelling of 161226778 in words is "one hundred sixty-one million, two hundred twenty-six thousand, seven hundred seventy-eight".