21278000415 has 32 divisors (see below), whose sum is σ = 38927370240. Its totient is φ = 9722329344.

The previous prime is 21278000407. The next prime is 21278000423. The reversal of 21278000415 is 51400087212.

It is an interprime number because it is at equal distance from previous prime (21278000407) and next prime (21278000423).

It is not a de Polignac number, because 21278000415 - 2³ = 21278000407 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 170842 + ... + 267848.

It is an arithmetic number, because the mean of its divisors is an integer number (1216480320).

Almost surely, 2^21278000415 is an apocalyptic number.

21278000415 is a deficient number, since it is larger than the sum of its proper divisors (17649369825).

21278000415 is a wasteful number, since it uses less digits than its factorization.

21278000415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99111.

The product of its (nonzero) digits is 4480, while the sum is 30.

Adding to 21278000415 its reverse (51400087212), we get a palindrome (72678087627).

The spelling of 21278000415 in words is "twenty-one billion, two hundred seventy-eight million, four hundred fifteen", and thus it is an aban number.