20645144140 has 24 divisors (see below), whose sum is σ = 43360107840. Its totient is φ = 8257047168.

The previous prime is 20645144119. The next prime is 20645144147. The reversal of 20645144140 is 4144154602.

It is a super-2 number, since 2×20645144140² (a number of 21 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 116896 + ... + 234424.

It is an arithmetic number, because the mean of its divisors is an integer number (1806671160).

Almost surely, 2^20645144140 is an apocalyptic number.

20645144140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20645144140 is an abundant number, since it is smaller than the sum of its proper divisors (22714963700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20645144140 is a wasteful number, since it uses less digits than its factorization.

20645144140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126321 (or 126319 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 31.

Adding to 20645144140 its reverse (4144154602), we get a palindrome (24789298742).

The spelling of 20645144140 in words is "twenty billion, six hundred forty-five million, one hundred forty-four thousand, one hundred forty".