20645361000 has 1280 divisors, whose sum is σ = 88067865600. Its totient is φ = 4451328000.

The previous prime is 20645360959. The next prime is 20645361013. The reversal of 20645361000 is 16354602.

20645361000 is a `hidden beast` number, since 2 + 0 + 6 + 45 + 3 + 610 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 439262977 + ... + 439263023.

It is an arithmetic number, because the mean of its divisors is an integer number (68803020).

Almost surely, 2^20645361000 is an apocalyptic number.

20645361000 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 20645361000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44033932800).

20645361000 is an abundant number, since it is smaller than the sum of its proper divisors (67422504600).

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

20645361000 is a wasteful number, since it uses less digits than its factorization.

20645361000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The spelling of 20645361000 in words is "twenty billion, six hundred forty-five million, three hundred sixty-one thousand".