209878464 has 56 divisors (see below), whose sum is σ = 587977488. Its totient is φ = 65843200.

The previous prime is 209878433. The next prime is 209878483. The reversal of 209878464 is 464878902.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28887 + ... + 35414.

It is an arithmetic number, because the mean of its divisors is an integer number (10499598).

Almost surely, 2^209878464 is an apocalyptic number.

209878464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

209878464 is an abundant number, since it is smaller than the sum of its proper divisors (378099024).

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

209878464 is a wasteful number, since it uses less digits than its factorization.

209878464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64333 (or 64323 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 48.

The square root of 209878464 is about 14487.1827488991. The cubic root of 209878464 is about 594.2775064026.

The spelling of 209878464 in words is "two hundred nine million, eight hundred seventy-eight thousand, four hundred sixty-four".