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21791090644 = 225879280703
BaseRepresentation
bin10100010010110110…
…011010011111010100
32002020122210002201021
4110102312122133110
5324112004400034
614002150410524
71401001133341
oct242266323724
962218702637
1021791090644
119272558a24
124281960a44
13209379869b
1410aa11d7c8
158781146b4
hex512d9a7d4

21791090644 has 12 divisors (see below), whose sum is σ = 38199377664. Its totient is φ = 10876982744.

The previous prime is 21791090641. The next prime is 21791090647. The reversal of 21791090644 is 44609019712.

It is an interprime number because it is at equal distance from previous prime (21791090641) and next prime (21791090647).

It is a self number, because there is not a number n which added to its sum of digits gives 21791090644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21791090641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4638004 + ... + 4642699.

It is an arithmetic number, because the mean of its divisors is an integer number (3183281472).

Almost surely, 221791090644 is an apocalyptic number.

It is an amenable number.

21791090644 is a deficient number, since it is larger than the sum of its proper divisors (16408287020).

21791090644 is a wasteful number, since it uses less digits than its factorization.

21791090644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9281294 (or 9281292 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 43.

The spelling of 21791090644 in words is "twenty-one billion, seven hundred ninety-one million, ninety thousand, six hundred forty-four".

Divisors: 1 2 4 587 1174 2348 9280703 18561406 37122812 5447772661 10895545322 21791090644