21728702 has 4 divisors (see below), whose sum is σ = 32593056. Its totient is φ = 10864350.

The previous prime is 21728699. The next prime is 21728719. The reversal of 21728702 is 20782712.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5432174 + ... + 5432177.

It is an arithmetic number, because the mean of its divisors is an integer number (8148264).

Almost surely, 2^21728702 is an apocalyptic number.

21728702 is a deficient number, since it is larger than the sum of its proper divisors (10864354).

21728702 is a wasteful number, since it uses less digits than its factorization.

21728702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10864353.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 21728702 is about 4661.4055820106. The cubic root of 21728702 is about 279.0473663067.

The spelling of 21728702 in words is "twenty-one million, seven hundred twenty-eight thousand, seven hundred two".