121821887 has 4 divisors (see below), whose sum is σ = 132896616. Its totient is φ = 110747160.

The previous prime is 121821859. The next prime is 121821893. The reversal of 121821887 is 788128121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121821887 - 2²⁶ = 54713023 is a prime.

It is a super-3 number, since 3×121821887³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121821887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121821827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5537348 + ... + 5537369.

It is an arithmetic number, because the mean of its divisors is an integer number (33224154).

Almost surely, 2^121821887 is an apocalyptic number.

121821887 is a deficient number, since it is larger than the sum of its proper divisors (11074729).

121821887 is a wasteful number, since it uses less digits than its factorization.

121821887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11074728.

The product of its digits is 14336, while the sum is 38.

The square root of 121821887 is about 11037.2952755646. The cubic root of 121821887 is about 495.7260874344.

The spelling of 121821887 in words is "one hundred twenty-one million, eight hundred twenty-one thousand, eight hundred eighty-seven".