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21111201 = 323763397
BaseRepresentation
bin101000010001…
…0000110100001
31110201120010100
41100202012201
520401024301
62032253013
7344304456
oct120420641
943646110
1021111201
1110a0a181
1270a1169
1344b2147
142b3782d
151cc0286
hex14221a1

21111201 has 12 divisors (see below), whose sum is σ = 31318612. Its totient is φ = 13693536.

The previous prime is 21111199. The next prime is 21111239. The reversal of 21111201 is 10211112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13950225 + 7160976 = 3735^2 + 2676^2 .

It is not a de Polignac number, because 21111201 - 21 = 21111199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31366 + ... + 32031.

Almost surely, 221111201 is an apocalyptic number.

It is an amenable number.

21111201 is a deficient number, since it is larger than the sum of its proper divisors (10207411).

21111201 is a wasteful number, since it uses less digits than its factorization.

21111201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63440 (or 63437 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 21111201 is about 4594.6926991911. The cubic root of 21111201 is about 276.3785369908.

Adding to 21111201 its reverse (10211112), we get a palindrome (31322313).

It can be divided in two parts, 21111 and 201, that added together give a palindrome (21312).

The spelling of 21111201 in words is "twenty-one million, one hundred eleven thousand, two hundred one".

Divisors: 1 3 9 37 111 333 63397 190191 570573 2345689 7037067 21111201