21620570 has 8 divisors (see below), whose sum is σ = 38917044. Its totient is φ = 8648224.

The previous prime is 21620569. The next prime is 21620579. The reversal of 21620570 is 7502612.

It can be written as a sum of positive squares in 2 ways, for example, as 19989841 + 1630729 = 4471^2 + 1277^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21620579) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1081019 + ... + 1081038.

Almost surely, 2^21620570 is an apocalyptic number.

21620570 is a deficient number, since it is larger than the sum of its proper divisors (17296474).

21620570 is a wasteful number, since it uses less digits than its factorization.

21620570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2162064.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21620570 is about 4649.7924684872. The cubic root of 21620570 is about 278.5837070447.

The spelling of 21620570 in words is "twenty-one million, six hundred twenty thousand, five hundred seventy".