207121540 has 96 divisors (see below), whose sum is σ = 487517184. Its totient is φ = 73543680.

The previous prime is 207121531. The next prime is 207121543. The reversal of 207121540 is 45121702.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (207121543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 452992 + ... + 453448.

It is an arithmetic number, because the mean of its divisors is an integer number (5078304).

Almost surely, 2^207121540 is an apocalyptic number.

207121540 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 207121540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243758592).

207121540 is an abundant number, since it is smaller than the sum of its proper divisors (280395644).

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

207121540 is a wasteful number, since it uses less digits than its factorization.

207121540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 207121540 is about 14391.7177570990. The cubic root of 207121540 is about 591.6639231066.

The spelling of 207121540 in words is "two hundred seven million, one hundred twenty-one thousand, five hundred forty".