21231011958 has 64 divisors (see below), whose sum is σ = 49436163840. Its totient is φ = 6021516672.

The previous prime is 21231011957. The next prime is 21231012041. The reversal of 21231011958 is 85911013212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231011957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 138760 + ... + 248427.

It is an arithmetic number, because the mean of its divisors is an integer number (772440060).

Almost surely, 2^21231011958 is an apocalyptic number.

21231011958 is an abundant number, since it is smaller than the sum of its proper divisors (28205151882).

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

21231011958 is a wasteful number, since it uses less digits than its factorization.

21231011958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387261.

The product of its (nonzero) digits is 4320, while the sum is 33.

The spelling of 21231011958 in words is "twenty-one billion, two hundred thirty-one million, eleven thousand, nine hundred fifty-eight".