21000422505 has 32 divisors (see below), whose sum is σ = 35388915840. Its totient is φ = 10604805120.

The previous prime is 21000422483. The next prime is 21000422557. The reversal of 21000422505 is 50522400012.

It is a happy number.

It is not a de Polignac number, because 21000422505 - 2⁶ = 21000422441 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 514135 + ... + 553475.

It is an arithmetic number, because the mean of its divisors is an integer number (1105903620).

Almost surely, 2^21000422505 is an apocalyptic number.

It is an amenable number.

21000422505 is a deficient number, since it is larger than the sum of its proper divisors (14388493335).

21000422505 is a wasteful number, since it uses less digits than its factorization.

21000422505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41241.

The product of its (nonzero) digits is 800, while the sum is 21.

Adding to 21000422505 its reverse (50522400012), we get a palindrome (71522822517).

The spelling of 21000422505 in words is "twenty-one billion, four hundred twenty-two thousand, five hundred five".