21829470 has 64 divisors (see below), whose sum is σ = 56899584. Its totient is φ = 5328000.

The previous prime is 21829463. The next prime is 21829477. The reversal of 21829470 is 7492812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21829463) and next prime (21829477).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21829477) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86845 + ... + 87095.

It is an arithmetic number, because the mean of its divisors is an integer number (889056).

Almost surely, 2^21829470 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21829470, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28449792).

21829470 is an abundant number, since it is smaller than the sum of its proper divisors (35070114).

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

21829470 is a wasteful number, since it uses less digits than its factorization.

21829470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21829470 is about 4672.2018363936. The cubic root of 21829470 is about 279.4780668121.

The spelling of 21829470 in words is "twenty-one million, eight hundred twenty-nine thousand, four hundred seventy".