1221606735278 has 8 divisors (see below), whose sum is σ = 1895596658280. Its totient is φ = 589741182520.

The previous prime is 1221606735233. The next prime is 1221606735299. The reversal of 1221606735278 is 8725376061221.

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

It is a congruent number.

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, 10531092488 + ... + 10531092603.

It is an arithmetic number, because the mean of its divisors is an integer number (236949582285).

Almost surely, 2^{1221606735278} is an apocalyptic number.

1221606735278 is a deficient number, since it is larger than the sum of its proper divisors (673989923002).

1221606735278 is a wasteful number, since it uses less digits than its factorization.

1221606735278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21062185122.

The product of its (nonzero) digits is 1693440, while the sum is 50.

The spelling of 1221606735278 in words is "one trillion, two hundred twenty-one billion, six hundred six million, seven hundred thirty-five thousand, two hundred seventy-eight".