21171426 has 16 divisors (see below), whose sum is σ = 44833824. Its totient is φ = 6641984.

The previous prime is 21171407. The next prime is 21171461. The reversal of 21171426 is 62417112.

It is a junction number, because it is equal to n+sod(n) for n = 21171396 and 21171405.

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, 103680 + ... + 103883.

It is an arithmetic number, because the mean of its divisors is an integer number (2802114).

Almost surely, 2^21171426 is an apocalyptic number.

21171426 is an abundant number, since it is smaller than the sum of its proper divisors (23662398).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21171426 is a wasteful number, since it uses less digits than its factorization.

21171426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207585.

The product of its digits is 672, while the sum is 24.

The square root of 21171426 is about 4601.2417889087. The cubic root of 21171426 is about 276.6411005230.

Adding to 21171426 its reverse (62417112), we get a palindrome (83588538).

The spelling of 21171426 in words is "twenty-one million, one hundred seventy-one thousand, four hundred twenty-six".