21010258 has 4 divisors (see below), whose sum is σ = 31515390. Its totient is φ = 10505128.

The previous prime is 21010237. The next prime is 21010259. The reversal of 21010258 is 85201012.

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

It can be written as a sum of positive squares in only one way, i.e., 15264649 + 5745609 = 3907^2 + 2397^2 .

It is not an unprimeable number, because it can be changed into a prime (21010259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5252563 + ... + 5252566.

Almost surely, 2^21010258 is an apocalyptic number.

21010258 is a deficient number, since it is larger than the sum of its proper divisors (10505132).

21010258 is a wasteful number, since it uses less digits than its factorization.

21010258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10505131.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 21010258 is about 4583.6947978678. The cubic root of 21010258 is about 275.9373326180.

The spelling of 21010258 in words is "twenty-one million, ten thousand, two hundred fifty-eight".