21661055120342 has 16 divisors (see below), whose sum is σ = 36114143358672. Its totient is φ = 9660161802720.

The previous prime is 21661055120333. The next prime is 21661055120347. The reversal of 21661055120342 is 24302155016612.

It is a super-4 number, since 4×21661055120342⁴ (a number of 54 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 21661055120296 and 21661055120305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661055120347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9288615953 + ... + 9288618284.

It is an arithmetic number, because the mean of its divisors is an integer number (2257133959917).

Almost surely, 2^{21661055120342} is an apocalyptic number.

21661055120342 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21661055120342 is a deficient number, since it is larger than the sum of its proper divisors (14453088238330).

21661055120342 is a wasteful number, since it uses less digits than its factorization.

21661055120342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18577234303.

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 21661055120342 in words is "twenty-one trillion, six hundred sixty-one billion, fifty-five million, one hundred twenty thousand, three hundred forty-two".