21020012412 has 48 divisors (see below), whose sum is σ = 56096742912. Its totient is φ = 6001070400.

The previous prime is 21020012399. The next prime is 21020012413. The reversal of 21020012412 is 21421002012.

It is a junction number, because it is equal to n+sod(n) for n = 21020012391 and 21020012400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020012413) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13113 + ... + 205455.

It is an arithmetic number, because the mean of its divisors is an integer number (1168682144).

Almost surely, 2^21020012412 is an apocalyptic number.

It is an amenable number.

21020012412 is an abundant number, since it is smaller than the sum of its proper divisors (35076730500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21020012412 is a wasteful number, since it uses less digits than its factorization.

21020012412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193658 (or 193656 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21020012412 its reverse (21421002012), we get a palindrome (42441014424).

The spelling of 21020012412 in words is "twenty-one billion, twenty million, twelve thousand, four hundred twelve".