21990183669 has 28 divisors (see below), whose sum is σ = 33098763756. Its totient is φ = 14602954752.

The previous prime is 21990183659. The next prime is 21990183671. The reversal of 21990183669 is 96638109912.

It can be written as a sum of positive squares in 2 ways, for example, as 18481043025 + 3509140644 = 135945^2 + 59238^2 .

It is not a de Polignac number, because 21990183669 - 2¹⁶ = 21990118133 is a prime.

It is a super-2 number, since 2×21990183669² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21990183629) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 128667 + ... + 246039.

Almost surely, 2^21990183669 is an apocalyptic number.

It is an amenable number.

21990183669 is a deficient number, since it is larger than the sum of its proper divisors (11108580087).

21990183669 is an equidigital number, since it uses as much as digits as its factorization.

21990183669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117648 (or 117633 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The spelling of 21990183669 in words is "twenty-one billion, nine hundred ninety million, one hundred eighty-three thousand, six hundred sixty-nine".