21661331703 has 16 divisors (see below), whose sum is σ = 31544112000. Its totient is φ = 13112779680.

The previous prime is 21661331701. The next prime is 21661331777. The reversal of 21661331703 is 30713316612.

It is not a de Polignac number, because 21661331703 - 2¹ = 21661331701 is a prime.

It is a super-2 number, since 2×21661331703² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661331701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 353728 + ... + 410421.

It is an arithmetic number, because the mean of its divisors is an integer number (1971507000).

Almost surely, 2^21661331703 is an apocalyptic number.

21661331703 is a deficient number, since it is larger than the sum of its proper divisors (9882780297).

21661331703 is a wasteful number, since it uses less digits than its factorization.

21661331703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765022.

The product of its (nonzero) digits is 13608, while the sum is 33.

The spelling of 21661331703 in words is "twenty-one billion, six hundred sixty-one million, three hundred thirty-one thousand, seven hundred three".