21870606 has 8 divisors (see below), whose sum is σ = 43741224. Its totient is φ = 7290200.

The previous prime is 21870599. The next prime is 21870643. The reversal of 21870606 is 60607812.

It is a happy number.

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

21870606 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1822545 + ... + 1822556.

It is an arithmetic number, because the mean of its divisors is an integer number (5467653).

Almost surely, 2^21870606 is an apocalyptic number.

21870606 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.

21870606 is a wasteful number, since it uses less digits than its factorization.

21870606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3645106.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 21870606 is about 4676.6019715174. The cubic root of 21870606 is about 279.6535084789.

The spelling of 21870606 in words is "twenty-one million, eight hundred seventy thousand, six hundred six".