21420501015212 has 24 divisors (see below), whose sum is σ = 40376252090496. Its totient is φ = 9884708431488.

The previous prime is 21420501015169. The next prime is 21420501015229. The reversal of 21420501015212 is 21251010502412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34620668 + ... + 35233955.

It is an arithmetic number, because the mean of its divisors is an integer number (1682343837104).

Almost surely, 2^{21420501015212} is an apocalyptic number.

It is an amenable number.

21420501015212 is a deficient number, since it is larger than the sum of its proper divisors (18955751075284).

21420501015212 is a wasteful number, since it uses less digits than its factorization.

21420501015212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69860537 (or 69860535 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 26.

Adding to 21420501015212 its reverse (21251010502412), we get a palindrome (42671511517624).

The spelling of 21420501015212 in words is "twenty-one trillion, four hundred twenty billion, five hundred one million, fifteen thousand, two hundred twelve".