21087815535830 has 32 divisors (see below), whose sum is σ = 38962314966528. Its totient is φ = 8214698448000.

The previous prime is 21087815535797. The next prime is 21087815535901. The reversal of 21087815535830 is 3853551878012.

It is a super-2 number, since 2×21087815535830² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

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, 171077942 + ... + 171201161.

It is an arithmetic number, because the mean of its divisors is an integer number (1217572342704).

Almost surely, 2^{21087815535830} is an apocalyptic number.

21087815535830 is a deficient number, since it is larger than the sum of its proper divisors (17874499430698).

21087815535830 is a wasteful number, since it uses less digits than its factorization.

21087815535830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342279272.

The product of its (nonzero) digits is 8064000, while the sum is 56.

The spelling of 21087815535830 in words is "twenty-one trillion, eighty-seven billion, eight hundred fifteen million, five hundred thirty-five thousand, eight hundred thirty".