21490129558 has 4 divisors (see below), whose sum is σ = 32235194340. Its totient is φ = 10745064778.

The previous prime is 21490129547. The next prime is 21490129559. The reversal of 21490129558 is 85592109412.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21490129559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5372532388 + ... + 5372532391.

It is an arithmetic number, because the mean of its divisors is an integer number (8058798585).

Almost surely, 2^21490129558 is an apocalyptic number.

21490129558 is a deficient number, since it is larger than the sum of its proper divisors (10745064782).

21490129558 is a wasteful number, since it uses less digits than its factorization.

21490129558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10745064781.

The product of its (nonzero) digits is 259200, while the sum is 46.

The spelling of 21490129558 in words is "twenty-one billion, four hundred ninety million, one hundred twenty-nine thousand, five hundred fifty-eight".