121727891 has 16 divisors (see below), whose sum is σ = 131156544. Its totient is φ = 112679424.

The previous prime is 121727887. The next prime is 121727897. The reversal of 121727891 is 198727121.

It is a cyclic number.

It is not a de Polignac number, because 121727891 - 2² = 121727887 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121727897) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 266135 + ... + 266591.

It is an arithmetic number, because the mean of its divisors is an integer number (8197284).

Almost surely, 2^121727891 is an apocalyptic number.

121727891 is a deficient number, since it is larger than the sum of its proper divisors (9428653).

121727891 is a wasteful number, since it uses less digits than its factorization.

121727891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830.

The product of its digits is 14112, while the sum is 38.

The square root of 121727891 is about 11033.0363454491. The cubic root of 121727891 is about 495.5985562768.

The spelling of 121727891 in words is "one hundred twenty-one million, seven hundred twenty-seven thousand, eight hundred ninety-one".