21013404212 has 6 divisors (see below), whose sum is σ = 36773457378. Its totient is φ = 10506702104.

The previous prime is 21013404211. The next prime is 21013404239. The reversal of 21013404212 is 21240431012.

It can be written as a sum of positive squares in only one way, i.e., 12842328976 + 8171075236 = 113324^2 + 90394^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013404211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2626675523 + ... + 2626675530.

It is an arithmetic number, because the mean of its divisors is an integer number (6128909563).

Almost surely, 2^21013404212 is an apocalyptic number.

It is an amenable number.

21013404212 is a deficient number, since it is larger than the sum of its proper divisors (15760053166).

21013404212 is a wasteful number, since it uses less digits than its factorization.

21013404212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5253351057 (or 5253351055 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21013404212 its reverse (21240431012), we get a palindrome (42253835224).

The spelling of 21013404212 in words is "twenty-one billion, thirteen million, four hundred four thousand, two hundred twelve".