21760638 has 8 divisors (see below), whose sum is σ = 43521288. Its totient is φ = 7253544.

The previous prime is 21760633. The next prime is 21760639. The reversal of 21760638 is 83606712.

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

21760638 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21760599 and 21760608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21760633) 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, 1813381 + ... + 1813392.

It is an arithmetic number, because the mean of its divisors is an integer number (5440161).

Almost surely, 2^21760638 is an apocalyptic number.

21760638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21760638 is a wasteful number, since it uses less digits than its factorization.

21760638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3626778.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 21760638 is about 4664.8299004358. The cubic root of 21760638 is about 279.1840103677.

The spelling of 21760638 in words is "twenty-one million, seven hundred sixty thousand, six hundred thirty-eight".