21061458 has 80 divisors (see below), whose sum is σ = 52690176. Its totient is φ = 6233760.

The previous prime is 21061451. The next prime is 21061459. The reversal of 21061458 is 85416012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21061451) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 94335 + ... + 94557.

Almost surely, 2^21061458 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21061458, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26345088).

21061458 is an abundant number, since it is smaller than the sum of its proper divisors (31628718).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21061458 is a wasteful number, since it uses less digits than its factorization.

21061458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21061458 is about 4589.2764135537. The cubic root of 21061458 is about 276.1612951343.

The spelling of 21061458 in words is "twenty-one million, sixty-one thousand, four hundred fifty-eight".