121820831 has 4 divisors (see below), whose sum is σ = 132895464. Its totient is φ = 110746200.

The previous prime is 121820819. The next prime is 121820869. The reversal of 121820831 is 138028121.

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 121820831 - 2¹⁴ = 121804447 is a prime.

It is a super-2 number, since 2×121820831² = 29680629731061122, which contains 22 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 121820831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121820131) 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, 5537300 + ... + 5537321.

It is an arithmetic number, because the mean of its divisors is an integer number (33223866).

Almost surely, 2^121820831 is an apocalyptic number.

121820831 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

121820831 is a deficient number, since it is larger than the sum of its proper divisors (11074633).

121820831 is a wasteful number, since it uses less digits than its factorization.

121820831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11074632.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 121820831 is about 11037.2474376540. The cubic root of 121820831 is about 495.7246550474.

Adding to 121820831 its reverse (138028121), we get a palindrome (259848952).

The spelling of 121820831 in words is "one hundred twenty-one million, eight hundred twenty thousand, eight hundred thirty-one".