161902778 has 8 divisors (see below), whose sum is σ = 242916672. Its totient is φ = 80930556.

The previous prime is 161902777. The next prime is 161902799. The reversal of 161902778 is 877209161.

161902778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not an unprimeable number, because it can be changed into a prime (161902777) 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, 2501 + ... + 18167.

It is an arithmetic number, because the mean of its divisors is an integer number (30364584).

Almost surely, 2^161902778 is an apocalyptic number.

161902778 is a deficient number, since it is larger than the sum of its proper divisors (81013894).

161902778 is a wasteful number, since it uses less digits than its factorization.

161902778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20836.

The product of its (nonzero) digits is 42336, while the sum is 41.

The square root of 161902778 is about 12724.1022473100. The cubic root of 161902778 is about 545.0271041145.

The spelling of 161902778 in words is "one hundred sixty-one million, nine hundred two thousand, seven hundred seventy-eight".