21405501145 has 8 divisors (see below), whose sum is σ = 29356115904. Its totient is φ = 14678057904.

The previous prime is 21405501133. The next prime is 21405501163. The reversal of 21405501145 is 54110550412.

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 21405501145 - 2⁷ = 21405501017 is a prime.

It is a super-2 number, since 2×21405501145² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305792839 + ... + 305792908.

It is an arithmetic number, because the mean of its divisors is an integer number (3669514488).

Almost surely, 2^21405501145 is an apocalyptic number.

It is an amenable number.

21405501145 is a deficient number, since it is larger than the sum of its proper divisors (7950614759).

21405501145 is an equidigital number, since it uses as much as digits as its factorization.

21405501145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611585759.

The product of its (nonzero) digits is 4000, while the sum is 28.

The spelling of 21405501145 in words is "twenty-one billion, four hundred five million, five hundred one thousand, one hundred forty-five".