21016513545 has 8 divisors (see below), whose sum is σ = 33626421696. Its totient is φ = 11208807216.

The previous prime is 21016513541. The next prime is 21016513571. The reversal of 21016513545 is 54531561012.

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

It is not a de Polignac number, because 21016513545 - 2² = 21016513541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21016513541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 700550437 + ... + 700550466.

It is an arithmetic number, because the mean of its divisors is an integer number (4203302712).

Almost surely, 2^21016513545 is an apocalyptic number.

It is an amenable number.

21016513545 is a deficient number, since it is larger than the sum of its proper divisors (12609908151).

21016513545 is a wasteful number, since it uses less digits than its factorization.

21016513545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1401100911.

The product of its (nonzero) digits is 18000, while the sum is 33.

The spelling of 21016513545 in words is "twenty-one billion, sixteen million, five hundred thirteen thousand, five hundred forty-five".