209401920 has 672 divisors, whose sum is σ = 958583808. Its totient is φ = 40697856.

The previous prime is 209401909. The next prime is 209401921. The reversal of 209401920 is 29104902.

It is a tau number, because it is divible by the number of its divisors (672).

It is not an unprimeable number, because it can be changed into a prime (209401921) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4455337 + ... + 4455383.

It is an arithmetic number, because the mean of its divisors is an integer number (1426464).

Almost surely, 2^209401920 is an apocalyptic number.

209401920 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 209401920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (479291904).

209401920 is an abundant number, since it is smaller than the sum of its proper divisors (749181888).

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

209401920 is a wasteful number, since it uses less digits than its factorization.

209401920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 209401920 is about 14470.7263121103. The cubic root of 209401920 is about 593.8273824168.

The spelling of 209401920 in words is "two hundred nine million, four hundred one thousand, nine hundred twenty".