21110420 has 24 divisors (see below), whose sum is σ = 45364704. Its totient is φ = 8247456.

The previous prime is 21110393. The next prime is 21110423. The reversal of 21110420 is 2401112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11414 + ... + 13133.

It is an arithmetic number, because the mean of its divisors is an integer number (1890196).

Almost surely, 2^21110420 is an apocalyptic number.

21110420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110420 is an abundant number, since it is smaller than the sum of its proper divisors (24254284).

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

21110420 is a wasteful number, since it uses less digits than its factorization.

21110420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24599 (or 24597 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21110420 is about 4594.6077090433. The cubic root of 21110420 is about 276.3751287795.

Adding to 21110420 its reverse (2401112), we get a palindrome (23511532).

The spelling of 21110420 in words is "twenty-one million, one hundred ten thousand, four hundred twenty".