21085157519 has 8 divisors (see below), whose sum is σ = 21148440960. Its totient is φ = 21021915096.

The previous prime is 21085157497. The next prime is 21085157537. The reversal of 21085157519 is 91575158012.

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

It is a cyclic number.

It is not a de Polignac number, because 21085157519 - 2¹⁶ = 21085091983 is a prime.

It is a super-2 number, since 2×21085157519² (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 21085157519.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21085150519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1244942 + ... + 1261764.

It is an arithmetic number, because the mean of its divisors is an integer number (2643555120).

Almost surely, 2^21085157519 is an apocalyptic number.

21085157519 is a deficient number, since it is larger than the sum of its proper divisors (63283441).

21085157519 is a wasteful number, since it uses less digits than its factorization.

21085157519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20509.

The product of its (nonzero) digits is 126000, while the sum is 44.

The spelling of 21085157519 in words is "twenty-one billion, eighty-five million, one hundred fifty-seven thousand, five hundred nineteen".