120821913 has 12 divisors (see below), whose sum is σ = 178234368. Its totient is φ = 78833880.

The previous prime is 120821881. The next prime is 120821923. The reversal of 120821913 is 319128021.

It is not a de Polignac number, because 120821913 - 2⁵ = 120821881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (120821923) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 142393 + ... + 143238.

It is an arithmetic number, because the mean of its divisors is an integer number (14852864).

Almost surely, 2^120821913 is an apocalyptic number.

It is an amenable number.

120821913 is a deficient number, since it is larger than the sum of its proper divisors (57412455).

120821913 is a wasteful number, since it uses less digits than its factorization.

120821913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285684 (or 285681 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 120821913 is about 10991.9021556781. The cubic root of 120821913 is about 494.3659712220.

Adding to 120821913 its reverse (319128021), we get a palindrome (439949934).

The spelling of 120821913 in words is "one hundred twenty million, eight hundred twenty-one thousand, nine hundred thirteen".