20661347145 has 16 divisors (see below), whose sum is σ = 33060827520. Its totient is φ = 11018494464.

The previous prime is 20661347131. The next prime is 20661347159. The reversal of 20661347145 is 54174316602.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20661347131) and next prime (20661347159).

It is not a de Polignac number, because 20661347145 - 2⁷ = 20661347017 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 164076 + ... + 261234.

It is an arithmetic number, because the mean of its divisors is an integer number (2066301720).

Almost surely, 2^20661347145 is an apocalyptic number.

It is an amenable number.

20661347145 is a deficient number, since it is larger than the sum of its proper divisors (12399480375).

20661347145 is a wasteful number, since it uses less digits than its factorization.

20661347145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111344.

The product of its (nonzero) digits is 120960, while the sum is 39.

The spelling of 20661347145 in words is "twenty billion, six hundred sixty-one million, three hundred forty-seven thousand, one hundred forty-five".