21150420491 has 8 divisors (see below), whose sum is σ = 21198840000. Its totient is φ = 21102056640.

The previous prime is 21150420481. The next prime is 21150420493. The reversal of 21150420491 is 19402405112.

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 21150420491 - 2¹⁸ = 21150158347 is a prime.

It is a super-2 number, since 2×21150420491² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21150420493) 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, 800510 + ... + 826508.

It is an arithmetic number, because the mean of its divisors is an integer number (2649855000).

Almost surely, 2^21150420491 is an apocalyptic number.

21150420491 is a deficient number, since it is larger than the sum of its proper divisors (48419509).

21150420491 is a wasteful number, since it uses less digits than its factorization.

21150420491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27829.

The product of its (nonzero) digits is 2880, while the sum is 29.

The spelling of 21150420491 in words is "twenty-one billion, one hundred fifty million, four hundred twenty thousand, four hundred ninety-one".