21712970 has 16 divisors (see below), whose sum is σ = 39143520. Its totient is φ = 8671824.

The previous prime is 21712963. The next prime is 21712973. The reversal of 21712970 is 7921712.

It is not an unprimeable number, because it can be changed into a prime (21712973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7601 + ... + 10059.

It is an arithmetic number, because the mean of its divisors is an integer number (2446470).

Almost surely, 2^21712970 is an apocalyptic number.

21712970 is a deficient number, since it is larger than the sum of its proper divisors (17430550).

21712970 is a wasteful number, since it uses less digits than its factorization.

21712970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3349.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21712970 is about 4659.7178026142. The cubic root of 21712970 is about 278.9800048191.

The spelling of 21712970 in words is "twenty-one million, seven hundred twelve thousand, nine hundred seventy".