19202121 has 12 divisors (see below), whose sum is σ = 27781572. Its totient is φ = 12780576.

The previous prime is 19202119. The next prime is 19202137. The reversal of 19202121 is 12120291.

It can be written as a sum of positive squares in 2 ways, for example, as 3686400 + 15515721 = 1920^2 + 3939^2 .

It is not a de Polignac number, because 19202121 - 2¹ = 19202119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19202094 and 19202103.

It is not an unprimeable number, because it can be changed into a prime (19202101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5835 + ... + 8511.

It is an arithmetic number, because the mean of its divisors is an integer number (2315131).

Almost surely, 2^19202121 is an apocalyptic number.

It is an amenable number.

19202121 is a deficient number, since it is larger than the sum of its proper divisors (8579451).

19202121 is a wasteful number, since it uses less digits than its factorization.

19202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3480 (or 3477 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 19202121 is about 4382.0224782627. The cubic root of 19202121 is about 267.7830398593.

The spelling of 19202121 in words is "nineteen million, two hundred two thousand, one hundred twenty-one".