21015042054 has 8 divisors (see below), whose sum is σ = 42030084120. Its totient is φ = 7005014016.

The previous prime is 21015042053. The next prime is 21015042079. The reversal of 21015042054 is 45024051012.

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

21015042054 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015042053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1751253499 + ... + 1751253510.

It is an arithmetic number, because the mean of its divisors is an integer number (5253760515).

Almost surely, 2^21015042054 is an apocalyptic number.

21015042054 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21015042054 is a wasteful number, since it uses less digits than its factorization.

21015042054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3502507014.

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 21015042054 its reverse (45024051012), we get a palindrome (66039093066).

The spelling of 21015042054 in words is "twenty-one billion, fifteen million, forty-two thousand, fifty-four".