21782030 has 8 divisors (see below), whose sum is σ = 39207672. Its totient is φ = 8712808.

The previous prime is 21782017. The next prime is 21782039. The reversal of 21782030 is 3028712.

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

It is a junction number, because it is equal to n+sod(n) for n = 21781987 and 21782005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21782039) 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, 1089092 + ... + 1089111.

It is an arithmetic number, because the mean of its divisors is an integer number (4900959).

Almost surely, 2^21782030 is an apocalyptic number.

21782030 is a deficient number, since it is larger than the sum of its proper divisors (17425642).

21782030 is a wasteful number, since it uses less digits than its factorization.

21782030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2178210.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21782030 is about 4667.1222396676. The cubic root of 21782030 is about 279.2754652288.

The spelling of 21782030 in words is "twenty-one million, seven hundred eighty-two thousand, thirty".