21235700447 has 16 divisors (see below), whose sum is σ = 23127144768. Its totient is φ = 19381697280.

The previous prime is 21235700401. The next prime is 21235700477. The reversal of 21235700447 is 74400753212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21235700447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235700477) 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, 873083 + ... + 897075.

It is an arithmetic number, because the mean of its divisors is an integer number (1445446548).

Almost surely, 2^21235700447 is an apocalyptic number.

21235700447 is a deficient number, since it is larger than the sum of its proper divisors (1891444321).

21235700447 is a wasteful number, since it uses less digits than its factorization.

21235700447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24770.

The product of its (nonzero) digits is 47040, while the sum is 35.

The spelling of 21235700447 in words is "twenty-one billion, two hundred thirty-five million, seven hundred thousand, four hundred forty-seven".