21030213508 has 24 divisors (see below), whose sum is σ = 36910150200. Its totient is φ = 10484490240.

The previous prime is 21030213499. The next prime is 21030213521. The reversal of 21030213508 is 80531203012.

It can be written as a sum of positive squares in 4 ways, for example, as 3772662084 + 17257551424 = 61422^2 + 131368^2 .

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, 3432688 + ... + 3438808.

It is an arithmetic number, because the mean of its divisors is an integer number (1537922925).

Almost surely, 2^21030213508 is an apocalyptic number.

It is an amenable number.

21030213508 is a deficient number, since it is larger than the sum of its proper divisors (15879936692).

21030213508 is a wasteful number, since it uses less digits than its factorization.

21030213508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8487 (or 8485 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The spelling of 21030213508 in words is "twenty-one billion, thirty million, two hundred thirteen thousand, five hundred eight".