21050154520 has 32 divisors (see below), whose sum is σ = 48165613200. Its totient is φ = 8277347968.

The previous prime is 21050154509. The next prime is 21050154557. The reversal of 21050154520 is 2545105012.

It is a congruent number.

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, 4457419 + ... + 4462138.

Almost surely, 2^21050154520 is an apocalyptic number.

21050154520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21050154520 is an abundant number, since it is smaller than the sum of its proper divisors (27115458680).

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

21050154520 is a wasteful number, since it uses less digits than its factorization.

21050154520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8919627 (or 8919623 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

Adding to 21050154520 its reverse (2545105012), we get a palindrome (23595259532).

The spelling of 21050154520 in words is "twenty-one billion, fifty million, one hundred fifty-four thousand, five hundred twenty".