21029706 has 24 divisors (see below), whose sum is σ = 47253024. Its totient is φ = 7009740.

The previous prime is 21029683. The next prime is 21029717. The reversal of 21029706 is 60792012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 21029706.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21150 + ... + 22121.

It is an arithmetic number, because the mean of its divisors is an integer number (1968876).

Almost surely, 2^21029706 is an apocalyptic number.

21029706 is an abundant number, since it is smaller than the sum of its proper divisors (26223318).

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

21029706 is an equidigital number, since it uses as much as digits as its factorization.

21029706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43288 (or 43276 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21029706 is about 4585.8157398657. The cubic root of 21029706 is about 276.0224461896.

The spelling of 21029706 in words is "twenty-one million, twenty-nine thousand, seven hundred six".