21300021958 has 4 divisors (see below), whose sum is σ = 31950032940. Its totient is φ = 10650010978.

The previous prime is 21300021943. The next prime is 21300021959. The reversal of 21300021958 is 85912000312.

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

It is a super-2 number, since 2×21300021958² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300021959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5325005488 + ... + 5325005491.

It is an arithmetic number, because the mean of its divisors is an integer number (7987508235).

Almost surely, 2^21300021958 is an apocalyptic number.

21300021958 is a deficient number, since it is larger than the sum of its proper divisors (10650010982).

21300021958 is a wasteful number, since it uses less digits than its factorization.

21300021958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10650010981.

The product of its (nonzero) digits is 4320, while the sum is 31.

The spelling of 21300021958 in words is "twenty-one billion, three hundred million, twenty-one thousand, nine hundred fifty-eight".