21158117542 has 8 divisors (see below), whose sum is σ = 33117053616. Its totient is φ = 10119099672.

The previous prime is 21158117521. The next prime is 21158117543. The reversal of 21158117542 is 24571185112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158117543) 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 in 3 ways as a sum of consecutive naturals, for example, 229979493 + ... + 229979584.

It is an arithmetic number, because the mean of its divisors is an integer number (4139631702).

Almost surely, 2^21158117542 is an apocalyptic number.

21158117542 is a deficient number, since it is larger than the sum of its proper divisors (11958936074).

21158117542 is a wasteful number, since it uses less digits than its factorization.

21158117542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459959102.

The product of its digits is 22400, while the sum is 37.

The spelling of 21158117542 in words is "twenty-one billion, one hundred fifty-eight million, one hundred seventeen thousand, five hundred forty-two".