21255070 has 16 divisors (see below), whose sum is σ = 38351088. Its totient is φ = 8481600.

The previous prime is 21255061. The next prime is 21255077. The reversal of 21255070 is 7055212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255077) 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, 2245 + ... + 6895.

It is an arithmetic number, because the mean of its divisors is an integer number (2396943).

Almost surely, 2^21255070 is an apocalyptic number.

21255070 is a deficient number, since it is larger than the sum of its proper divisors (17096018).

21255070 is a wasteful number, since it uses less digits than its factorization.

21255070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5115.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 21255070 is about 4610.3221145599. The cubic root of 21255070 is about 277.0049393742.

The spelling of 21255070 in words is "twenty-one million, two hundred fifty-five thousand, seventy".