21973458 has 32 divisors (see below), whose sum is σ = 48488832. Its totient is φ = 6595200.

The previous prime is 21973453. The next prime is 21973463. The reversal of 21973458 is 85437912.

It is an interprime number because it is at equal distance from previous prime (21973453) and next prime (21973463).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (21973453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 238 + ... + 6633.

It is an arithmetic number, because the mean of its divisors is an integer number (1515276).

Almost surely, 2^21973458 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21973458, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24244416).

21973458 is an abundant number, since it is smaller than the sum of its proper divisors (26515374).

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

21973458 is a wasteful number, since it uses less digits than its factorization.

21973458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6930.

The product of its digits is 60480, while the sum is 39.

The square root of 21973458 is about 4687.5855192199. The cubic root of 21973458 is about 280.0912032827.

The spelling of 21973458 in words is "twenty-one million, nine hundred seventy-three thousand, four hundred fifty-eight".