21013000 has 32 divisors (see below), whose sum is σ = 49172760. Its totient is φ = 8404800.

The previous prime is 21012997. The next prime is 21013019. The reversal of 21013000 is 31012.

It can be written as a sum of positive squares in 4 ways, for example, as 708964 + 20304036 = 842^2 + 4506^2 .

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, 9507 + ... + 11506.

Almost surely, 2^21013000 is an apocalyptic number.

21013000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21013000 is an abundant number, since it is smaller than the sum of its proper divisors (28159760).

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

21013000 is a wasteful number, since it uses less digits than its factorization.

21013000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21034 (or 21020 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 7.

The square root of 21013000 is about 4583.9938917935. The cubic root of 21013000 is about 275.9493360761.

Adding to 21013000 its reverse (31012), we get a palindrome (21044012).

The spelling of 21013000 in words is "twenty-one million, thirteen thousand".