21180426 has 8 divisors (see below), whose sum is σ = 42360864. Its totient is φ = 7060140.

The previous prime is 21180413. The next prime is 21180431. The reversal of 21180426 is 62408112.

It is a sphenic number, since it is the product of 3 distinct primes.

21180426 is an admirable number.

It is a super-2 number, since 2×21180426² = 897220891082952, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21180396 and 21180405.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1765030 + ... + 1765041.

It is an arithmetic number, because the mean of its divisors is an integer number (5295108).

Almost surely, 2^21180426 is an apocalyptic number.

21180426 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21180426 is a wasteful number, since it uses less digits than its factorization.

21180426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3530076.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 21180426 is about 4602.2196818492. The cubic root of 21180426 is about 276.6802951303.

Adding to 21180426 its reverse (62408112), we get a palindrome (83588538).

The spelling of 21180426 in words is "twenty-one million, one hundred eighty thousand, four hundred twenty-six".