20645163344531 has 16 divisors (see below), whose sum is σ = 23708368803840. Its totient is φ = 17779770306720.

The previous prime is 20645163344489. The next prime is 20645163344557. The reversal of 20645163344531 is 13544336154602.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20645163344531 - 2⁶ = 20645163344467 is a prime.

It is a super-2 number, since 2×20645163344531² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20645163344581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2882081 + ... + 7042493.

It is an arithmetic number, because the mean of its divisors is an integer number (1481773050240).

Almost surely, 2^{20645163344531} is an apocalyptic number.

20645163344531 is a deficient number, since it is larger than the sum of its proper divisors (3063205459309).

20645163344531 is a wasteful number, since it uses less digits than its factorization.

20645163344531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4184186.

The product of its (nonzero) digits is 3110400, while the sum is 47.

The spelling of 20645163344531 in words is "twenty trillion, six hundred forty-five billion, one hundred sixty-three million, three hundred forty-four thousand, five hundred thirty-one".