21661020001230 has 16 divisors (see below), whose sum is σ = 51986448003024. Its totient is φ = 5776272000320.

The previous prime is 21661020001223. The next prime is 21661020001303. The reversal of 21661020001230 is 3210002016612.

It is a super-2 number, since 2×21661020001230² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21661020001230.

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, 361016999991 + ... + 361017000050.

It is an arithmetic number, because the mean of its divisors is an integer number (3249153000189).

Almost surely, 2^{21661020001230} is an apocalyptic number.

21661020001230 is an abundant number, since it is smaller than the sum of its proper divisors (30325428001794).

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

21661020001230 is a wasteful number, since it uses less digits than its factorization.

21661020001230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722034000051.

The product of its (nonzero) digits is 864, while the sum is 24.

Adding to 21661020001230 its reverse (3210002016612), we get a palindrome (24871022017842).

The spelling of 21661020001230 in words is "twenty-one trillion, six hundred sixty-one billion, twenty million, one thousand, two hundred thirty".