21856621241 has 32 divisors (see below), whose sum is σ = 27652934400. Its totient is φ = 16810281216.

The previous prime is 21856621211. The next prime is 21856621273. The reversal of 21856621241 is 14212665812.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21856621241 - 2¹⁰ = 21856620217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21856621195 and 21856621204.

It is not an unprimeable number, because it can be changed into a prime (21856621211) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4802435 + ... + 4806983.

It is an arithmetic number, because the mean of its divisors is an integer number (864154200).

Almost surely, 2^21856621241 is an apocalyptic number.

It is an amenable number.

21856621241 is a deficient number, since it is larger than the sum of its proper divisors (5796313159).

21856621241 is a wasteful number, since it uses less digits than its factorization.

21856621241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6033.

The product of its digits is 46080, while the sum is 38.

The spelling of 21856621241 in words is "twenty-one billion, eight hundred fifty-six million, six hundred twenty-one thousand, two hundred forty-one".