21012332421 has 8 divisors (see below), whose sum is σ = 28017255040. Its totient is φ = 14007815712.

The previous prime is 21012332377. The next prime is 21012332431. The reversal of 21012332421 is 12423321012.

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

It is not a de Polignac number, because 21012332421 - 2⁷ = 21012332293 is a prime.

It is a super-2 number, since 2×21012332421² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012332431) 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, 52836 + ... + 211698.

It is an arithmetic number, because the mean of its divisors is an integer number (3502156880).

Almost surely, 2^21012332421 is an apocalyptic number.

It is an amenable number.

21012332421 is a deficient number, since it is larger than the sum of its proper divisors (7004922619).

21012332421 is a wasteful number, since it uses less digits than its factorization.

21012332421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202955.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21012332421 its reverse (12423321012), we get a palindrome (33435653433).

The spelling of 21012332421 in words is "twenty-one billion, twelve million, three hundred thirty-two thousand, four hundred twenty-one".