20154352640 has 88 divisors (see below), whose sum is σ = 48406800960. Its totient is φ = 8051744768.

The previous prime is 20154352637. The next prime is 20154352651. The reversal of 20154352640 is 4625345102.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 20154352597 and 20154352606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5215349 + ... + 5219211.

Almost surely, 2^20154352640 is an apocalyptic number.

20154352640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20154352640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24203400480).

20154352640 is an abundant number, since it is smaller than the sum of its proper divisors (28252448320).

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

20154352640 is a wasteful number, since it uses less digits than its factorization.

20154352640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4907 (or 4889 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 20154352640 its reverse (4625345102), we get a palindrome (24779697742).

The spelling of 20154352640 in words is "twenty billion, one hundred fifty-four million, three hundred fifty-two thousand, six hundred forty".