21571070 has 16 divisors (see below), whose sum is σ = 40167360. Its totient is φ = 8330784.

The previous prime is 21571057. The next prime is 21571087. The reversal of 21571070 is 7017512.

It is a happy number.

It is a super-2 number, since 2×21571070² = 930622121889800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36902 + ... + 37481.

It is an arithmetic number, because the mean of its divisors is an integer number (2510460).

Almost surely, 2^21571070 is an apocalyptic number.

21571070 is a deficient number, since it is larger than the sum of its proper divisors (18596290).

21571070 is a wasteful number, since it uses less digits than its factorization.

21571070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74419.

The product of its (nonzero) digits is 490, while the sum is 23.

The square root of 21571070 is about 4644.4666001598. The cubic root of 21571070 is about 278.3709400543.

Adding to 21571070 its reverse (7017512), we get a palindrome (28588582).

The spelling of 21571070 in words is "twenty-one million, five hundred seventy-one thousand, seventy".