21278598086 has 4 divisors (see below), whose sum is σ = 31917897132. Its totient is φ = 10639299042.

The previous prime is 21278598083. The next prime is 21278598091. The reversal of 21278598086 is 68089587212.

It is a happy number.

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 (21278598083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5319649520 + ... + 5319649523.

It is an arithmetic number, because the mean of its divisors is an integer number (7979474283).

Almost surely, 2^21278598086 is an apocalyptic number.

21278598086 is a deficient number, since it is larger than the sum of its proper divisors (10639299046).

21278598086 is a wasteful number, since it uses less digits than its factorization.

21278598086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10639299045.

The product of its (nonzero) digits is 3870720, while the sum is 56.

The spelling of 21278598086 in words is "twenty-one billion, two hundred seventy-eight million, five hundred ninety-eight thousand, eighty-six".