121663778 has 8 divisors (see below), whose sum is σ = 188382720. Its totient is φ = 58869540.

The previous prime is 121663757. The next prime is 121663811. The reversal of 121663778 is 877366121.

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

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, 981098 + ... + 981221.

It is an arithmetic number, because the mean of its divisors is an integer number (23547840).

Almost surely, 2^121663778 is an apocalyptic number.

121663778 is a deficient number, since it is larger than the sum of its proper divisors (66718942).

121663778 is a wasteful number, since it uses less digits than its factorization.

121663778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1962352.

The product of its digits is 84672, while the sum is 41.

The square root of 121663778 is about 11030.1304616038. The cubic root of 121663778 is about 495.5115318761.

The spelling of 121663778 in words is "one hundred twenty-one million, six hundred sixty-three thousand, seven hundred seventy-eight".