21150020 has 24 divisors (see below), whose sum is σ = 44850624. Its totient is φ = 8377056.

The previous prime is 21150011. The next prime is 21150037. The reversal of 21150020 is 2005112.

It is a junction number, because it is equal to n+sod(n) for n = 21149983 and 21150010.

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, 3074 + ... + 7193.

It is an arithmetic number, because the mean of its divisors is an integer number (1868776).

Almost surely, 2^21150020 is an apocalyptic number.

21150020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21150020 is an abundant number, since it is smaller than the sum of its proper divisors (23700604).

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

21150020 is a wasteful number, since it uses less digits than its factorization.

21150020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10379 (or 10377 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 21150020 is about 4598.9150894532. The cubic root of 21150020 is about 276.5478336781.

21150020 divided by its product of nonzero digits (20) gives a palindrome (1057501).

Adding to 21150020 its reverse (2005112), we get a palindrome (23155132).

The spelling of 21150020 in words is "twenty-one million, one hundred fifty thousand, twenty".