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12987961 = 71855423
BaseRepresentation
bin110001100010…
…111000111001
3220102212010121
4301202320321
511311103321
61142213241
7215252530
oct61427071
926385117
1012987961
117371058
124424221
1328c98ac
141a21317
151218441
hexc62e39

12987961 has 4 divisors (see below), whose sum is σ = 14843392. Its totient is φ = 11132532.

The previous prime is 12987917. The next prime is 12987967. The reversal of 12987961 is 16978921.

12987961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12987961 - 27 = 12987833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12987967) 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, 927705 + ... + 927718.

It is an arithmetic number, because the mean of its divisors is an integer number (3710848).

Almost surely, 212987961 is an apocalyptic number.

It is an amenable number.

12987961 is a deficient number, since it is larger than the sum of its proper divisors (1855431).

12987961 is an equidigital number, since it uses as much as digits as its factorization.

12987961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1855430.

The product of its digits is 54432, while the sum is 43.

The square root of 12987961 is about 3603.8813798459. The cubic root of 12987961 is about 235.0608624614.

The spelling of 12987961 in words is "twelve million, nine hundred eighty-seven thousand, nine hundred sixty-one".

Divisors: 1 7 1855423 12987961