21154285619 has 4 divisors (see below), whose sum is σ = 21166494096. Its totient is φ = 21142077144.

The previous prime is 21154285609. The next prime is 21154285723. The reversal of 21154285619 is 91658245112.

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

It is a cyclic number.

It is not a de Polignac number, because 21154285619 - 2¹² = 21154281523 is a prime.

It is a super-2 number, since 2×21154285619² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21154285619.

It is not an unprimeable number, because it can be changed into a prime (21154285609) 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, 6101639 + ... + 6105104.

It is an arithmetic number, because the mean of its divisors is an integer number (5291623524).

Almost surely, 2^21154285619 is an apocalyptic number.

21154285619 is a deficient number, since it is larger than the sum of its proper divisors (12208477).

21154285619 is a wasteful number, since it uses less digits than its factorization.

21154285619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12208476.

The product of its digits is 172800, while the sum is 44.

The spelling of 21154285619 in words is "twenty-one billion, one hundred fifty-four million, two hundred eighty-five thousand, six hundred nineteen".