21310420 has 24 divisors (see below), whose sum is σ = 46698624. Its totient is φ = 8153376.

The previous prime is 21310417. The next prime is 21310433. The reversal of 21310420 is 2401312.

It is a super-3 number, since 3×21310420³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21310420.

It is a congruent number.

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, 22704 + ... + 23623.

It is an arithmetic number, because the mean of its divisors is an integer number (1945776).

Almost surely, 2^21310420 is an apocalyptic number.

21310420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21310420 is an abundant number, since it is smaller than the sum of its proper divisors (25388204).

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

21310420 is a wasteful number, since it uses less digits than its factorization.

21310420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46359 (or 46357 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21310420 is about 4616.3210460279. The cubic root of 21310420 is about 277.2451790568.

Adding to 21310420 its reverse (2401312), we get a palindrome (23711732).

The spelling of 21310420 in words is "twenty-one million, three hundred ten thousand, four hundred twenty".