21278632858 has 16 divisors (see below), whose sum is σ = 36526769280. Its totient is φ = 9107135856.

The previous prime is 21278632831. The next prime is 21278632871. The reversal of 21278632858 is 85823687212.

It is a super-3 number, since 3×21278632858³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1012413 + ... + 1033216.

It is an arithmetic number, because the mean of its divisors is an integer number (2282923080).

Almost surely, 2^21278632858 is an apocalyptic number.

21278632858 is a deficient number, since it is larger than the sum of its proper divisors (15248136422).

21278632858 is a wasteful number, since it uses less digits than its factorization.

21278632858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2046381.

The product of its digits is 2580480, while the sum is 52.

The spelling of 21278632858 in words is "twenty-one billion, two hundred seventy-eight million, six hundred thirty-two thousand, eight hundred fifty-eight".