20645144157 has 16 divisors (see below), whose sum is σ = 30180211200. Its totient is φ = 12449329200.

The previous prime is 20645144147. The next prime is 20645144213. The reversal of 20645144157 is 75144154602.

It is not a de Polignac number, because 20645144157 - 2¹⁰ = 20645143133 is a prime.

It is a super-2 number, since 2×20645144157² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645144147) 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, 1565319 + ... + 1578452.

It is an arithmetic number, because the mean of its divisors is an integer number (1886263200).

Almost surely, 2^20645144157 is an apocalyptic number.

It is an amenable number.

20645144157 is a deficient number, since it is larger than the sum of its proper divisors (9535067043).

20645144157 is a wasteful number, since it uses less digits than its factorization.

20645144157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3143984.

The product of its (nonzero) digits is 134400, while the sum is 39.

Adding to 20645144157 its reverse (75144154602), we get a palindrome (95789298759).

The spelling of 20645144157 in words is "twenty billion, six hundred forty-five million, one hundred forty-four thousand, one hundred fifty-seven".