216705400 has 48 divisors (see below), whose sum is σ = 521227800. Its totient is φ = 83690880.

The previous prime is 216705397. The next prime is 216705449. The reversal of 216705400 is 4507612.

It is a super-2 number, since 2×216705400² = 93922460778320000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12882 + ... + 24481.

Almost surely, 2^216705400 is an apocalyptic number.

216705400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216705400 is an abundant number, since it is smaller than the sum of its proper divisors (304522400).

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

216705400 is a wasteful number, since it uses less digits than its factorization.

216705400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37408 (or 37399 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 216705400 is about 14720.9170909967. The cubic root of 216705400 is about 600.6524384311.

The spelling of 216705400 in words is "two hundred sixteen million, seven hundred five thousand, four hundred".