21136145745 has 32 divisors (see below), whose sum is σ = 39730045824. Its totient is φ = 9459532800.

The previous prime is 21136145741. The next prime is 21136145783. The reversal of 21136145745 is 54754163112.

It is not a de Polignac number, because 21136145745 - 2² = 21136145741 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (21136145741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4924696 + ... + 4928985.

It is an arithmetic number, because the mean of its divisors is an integer number (1241563932).

Almost surely, 2^21136145745 is an apocalyptic number.

It is an amenable number.

21136145745 is a deficient number, since it is larger than the sum of its proper divisors (18593900079).

21136145745 is a wasteful number, since it uses less digits than its factorization.

21136145745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9853713.

The product of its digits is 100800, while the sum is 39.

The spelling of 21136145745 in words is "twenty-one billion, one hundred thirty-six million, one hundred forty-five thousand, seven hundred forty-five".