21129992145 has 48 divisors (see below), whose sum is σ = 37126252800. Its totient is φ = 11115486720.

The previous prime is 21129992123. The next prime is 21129992179. The reversal of 21129992145 is 54129992112.

21129992145 is a `hidden beast` number, since 211 + 299 + 9 + 2 + 145 = 666.

It is not a de Polignac number, because 21129992145 - 2⁸ = 21129991889 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21129992145.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 4473385 + ... + 4478105.

It is an arithmetic number, because the mean of its divisors is an integer number (773463600).

Almost surely, 2^21129992145 is an apocalyptic number.

It is an amenable number.

21129992145 is a deficient number, since it is larger than the sum of its proper divisors (15996260655).

21129992145 is a wasteful number, since it uses less digits than its factorization.

21129992145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6070 (or 6067 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The spelling of 21129992145 in words is "twenty-one billion, one hundred twenty-nine million, nine hundred ninety-two thousand, one hundred forty-five".