21470020 has 48 divisors (see below), whose sum is σ = 52976448. Its totient is φ = 7205760.

The previous prime is 21469999. The next prime is 21470047. The reversal of 21470020 is 2007412.

It is a junction number, because it is equal to n+sod(n) for n = 21469976 and 21470003.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 894 + ... + 6613.

It is an arithmetic number, because the mean of its divisors is an integer number (1103676).

Almost surely, 2^21470020 is an apocalyptic number.

21470020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21470020 is an abundant number, since it is smaller than the sum of its proper divisors (31506428).

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

21470020 is a wasteful number, since it uses less digits than its factorization.

21470020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7540 (or 7538 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 21470020 is about 4633.5752934424. The cubic root of 21470020 is about 277.9355819205.

Adding to 21470020 its reverse (2007412), we get a palindrome (23477432).

The spelling of 21470020 in words is "twenty-one million, four hundred seventy thousand, twenty".