21209852641 has 24 divisors (see below), whose sum is σ = 22703750784. Its totient is φ = 19800782400.

The previous prime is 21209852633. The next prime is 21209852693. The reversal of 21209852641 is 14625890212.

It is a happy number.

It is not a de Polignac number, because 21209852641 - 2³ = 21209852633 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21209852594 and 21209852603.

It is not an unprimeable number, because it can be changed into a prime (21209852611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3649560 + ... + 3655366.

It is an arithmetic number, because the mean of its divisors is an integer number (945989616).

Almost surely, 2^21209852641 is an apocalyptic number.

It is an amenable number.

21209852641 is a deficient number, since it is larger than the sum of its proper divisors (1493898143).

21209852641 is a wasteful number, since it uses less digits than its factorization.

21209852641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6009 (or 5980 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 21209852641 in words is "twenty-one billion, two hundred nine million, eight hundred fifty-two thousand, six hundred forty-one".