20402121 has 8 divisors (see below), whose sum is σ = 27649024. Its totient is φ = 13378320.

The previous prime is 20402119. The next prime is 20402131. The reversal of 20402121 is 12120402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20402121 - 2¹ = 20402119 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20402097 and 20402106.

It is not an unprimeable number, because it can be changed into a prime (20402131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55561 + ... + 55926.

It is an arithmetic number, because the mean of its divisors is an integer number (3456128).

Almost surely, 2^20402121 is an apocalyptic number.

It is an amenable number.

20402121 is a deficient number, since it is larger than the sum of its proper divisors (7246903).

20402121 is a wasteful number, since it uses less digits than its factorization.

20402121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111551.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 20402121 is about 4516.8707087983. The cubic root of 20402121 is about 273.2489109031.

Adding to 20402121 its reverse (12120402), we get a palindrome (32522523).

It can be divided in two parts, 20402 and 121, that multiplied together give a palindrome (2468642).

The spelling of 20402121 in words is "twenty million, four hundred two thousand, one hundred twenty-one".