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10638991 = 111756893

10638991 has 8 divisors (see below), whose sum is σ = 12289104. Its totient is φ = 9102720.

The previous prime is 10638989. The next prime is 10639001. The reversal of 10638991 is 19983601.

10638991 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 10638991 - 21 = 10638989 is a prime.

It is a super-2 number, since 2×106389912 = 226376258996162, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 10638991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10638961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28260 + ... + 28633.

It is an arithmetic number, because the mean of its divisors is an integer number (1536138).

Almost surely, 210638991 is an apocalyptic number.

10638991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

10638991 is a deficient number, since it is larger than the sum of its proper divisors (1650113).

10638991 is a wasteful number, since it uses less digits than its factorization.

10638991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56921.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 10638991 is about 3261.7466179947. The cubic root of 10638991 is about 219.9379370389.

The spelling of 10638991 in words is "ten million, six hundred thirty-eight thousand, nine hundred ninety-one".

Divisors: 1 11 17 187 56893 625823 967181 10638991