21661058 has 8 divisors (see below), whose sum is σ = 33369852. Its totient is φ = 10537776.

The previous prime is 21661051. The next prime is 21661061. The reversal of 21661058 is 85016612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14569489 + 7091569 = 3817^2 + 2663^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21661058.

It is not an unprimeable number, because it can be changed into a prime (21661051) 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, 146285 + ... + 146432.

Almost surely, 2^21661058 is an apocalyptic number.

21661058 is a deficient number, since it is larger than the sum of its proper divisors (11708794).

21661058 is a wasteful number, since it uses less digits than its factorization.

21661058 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292756.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21661058 is about 4654.1441748188. The cubic root of 21661058 is about 278.7574962291.

The spelling of 21661058 in words is "twenty-one million, six hundred sixty-one thousand, fifty-eight".