209256138000 has 1440 divisors, whose sum is σ = 936586340352. Its totient is φ = 42591744000.

The previous prime is 209256137999. The next prime is 209256138017. The reversal of 209256138000 is 831652902.

209256138000 is a `hidden beast` number, since 2 + 0 + 92 + 561 + 3 + 8 + 0 + 0 + 0 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 660113842 + ... + 660114158.

Almost surely, 2^209256138000 is an apocalyptic number.

209256138000 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 209256138000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (468293170176).

209256138000 is an abundant number, since it is smaller than the sum of its proper divisors (727330202352).

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

209256138000 is a wasteful number, since it uses less digits than its factorization.

209256138000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 209256138000 in words is "two hundred nine billion, two hundred fifty-six million, one hundred thirty-eight thousand".