20521213402 has 8 divisors (see below), whose sum is σ = 30782445300. Its totient is φ = 10260398304.

The previous prime is 20521213369. The next prime is 20521213409. The reversal of 20521213402 is 20431212502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17736646041 + 2784567361 = 133179^2 + 52769^2 .

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

It is a super-2 number, since 2×20521213402² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521213409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95224 + ... + 223852.

Almost surely, 2^20521213402 is an apocalyptic number.

20521213402 is a deficient number, since it is larger than the sum of its proper divisors (10261231898).

20521213402 is a wasteful number, since it uses less digits than its factorization.

20521213402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208400.

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 20521213402 its reverse (20431212502), we get a palindrome (40952425904).

The spelling of 20521213402 in words is "twenty billion, five hundred twenty-one million, two hundred thirteen thousand, four hundred two".