212491540 has 12 divisors (see below), whose sum is σ = 446232276. Its totient is φ = 84996608.

The previous prime is 212491507. The next prime is 212491553. The reversal of 212491540 is 45194212.

It can be written as a sum of positive squares in 2 ways, for example, as 147914244 + 64577296 = 12162^2 + 8036^2 .

It is a junction number, because it is equal to n+sod(n) for n = 212491499 and 212491508.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5312269 + ... + 5312308.

It is an arithmetic number, because the mean of its divisors is an integer number (37186023).

Almost surely, 2^212491540 is an apocalyptic number.

212491540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212491540 is an abundant number, since it is smaller than the sum of its proper divisors (233740736).

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

212491540 is a wasteful number, since it uses less digits than its factorization.

212491540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10624586 (or 10624584 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 212491540 is about 14577.0895586190. The cubic root of 212491540 is about 596.7336767466.

The spelling of 212491540 in words is "two hundred twelve million, four hundred ninety-one thousand, five hundred forty".