21858536894 has 4 divisors (see below), whose sum is σ = 32787805344. Its totient is φ = 10929268446.

The previous prime is 21858536893. The next prime is 21858536899. The reversal of 21858536894 is 49863585812.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21858536893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5464634222 + ... + 5464634225.

It is an arithmetic number, because the mean of its divisors is an integer number (8196951336).

Almost surely, 2^21858536894 is an apocalyptic number.

21858536894 is a deficient number, since it is larger than the sum of its proper divisors (10929268450).

21858536894 is a wasteful number, since it uses less digits than its factorization.

21858536894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10929268449.

The product of its digits is 16588800, while the sum is 59.

The spelling of 21858536894 in words is "twenty-one billion, eight hundred fifty-eight million, five hundred thirty-six thousand, eight hundred ninety-four".