20351102640 has 160 divisors (see below), whose sum is σ = 71197228800. Its totient is φ = 4763458560.

The previous prime is 20351102633. The next prime is 20351102659. The reversal of 20351102640 is 4620115302.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20351102640.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 56350 + ... + 209469.

It is an arithmetic number, because the mean of its divisors is an integer number (444982680).

Almost surely, 2^20351102640 is an apocalyptic number.

20351102640 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 20351102640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35598614400).

20351102640 is an abundant number, since it is smaller than the sum of its proper divisors (50846126160).

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

20351102640 is a wasteful number, since it uses less digits than its factorization.

20351102640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265875 (or 265869 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

Adding to 20351102640 its reverse (4620115302), we get a palindrome (24971217942).

The spelling of 20351102640 in words is "twenty billion, three hundred fifty-one million, one hundred two thousand, six hundred forty".