20645171400 has 192 divisors, whose sum is σ = 73524758400. Its totient is φ = 4694261760.

The previous prime is 20645171347. The next prime is 20645171479. The reversal of 20645171400 is 417154602.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 797866 + ... + 823334.

It is an arithmetic number, because the mean of its divisors is an integer number (382941450).

Almost surely, 2^20645171400 is an apocalyptic number.

20645171400 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 20645171400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36762379200).

20645171400 is an abundant number, since it is smaller than the sum of its proper divisors (52879587000).

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

20645171400 is a wasteful number, since it uses less digits than its factorization.

20645171400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25688 (or 25679 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The spelling of 20645171400 in words is "twenty billion, six hundred forty-five million, one hundred seventy-one thousand, four hundred".