213777540 has 72 divisors (see below), whose sum is σ = 653267160. Its totient is φ = 56584704.

The previous prime is 213777523. The next prime is 213777559. The reversal of 213777540 is 45777312.

It can be written as a sum of positive squares in 4 ways, for example, as 23503104 + 190274436 = 4848^2 + 13794^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 213777495 and 213777504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20326 + ... + 28994.

It is an arithmetic number, because the mean of its divisors is an integer number (9073155).

Almost surely, 2^213777540 is an apocalyptic number.

213777540 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 213777540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326633580).

213777540 is an abundant number, since it is smaller than the sum of its proper divisors (439489620).

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

213777540 is a wasteful number, since it uses less digits than its factorization.

213777540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8821 (or 8816 counting only the distinct ones).

The product of its (nonzero) digits is 41160, while the sum is 36.

The square root of 213777540 is about 14621.1333350052. The cubic root of 213777540 is about 597.9350682473.

The spelling of 213777540 in words is "two hundred thirteen million, seven hundred seventy-seven thousand, five hundred forty".