140387521 has 4 divisors (see below), whose sum is σ = 145228500. Its totient is φ = 135546544.

The previous prime is 140387497. The next prime is 140387551. The reversal of 140387521 is 125783041.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52403121 + 87984400 = 7239^2 + 9380^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-140387521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (140387551) 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 3 ways as a sum of consecutive naturals, for example, 2420446 + ... + 2420503.

It is an arithmetic number, because the mean of its divisors is an integer number (36307125).

Almost surely, 2^140387521 is an apocalyptic number.

It is an amenable number.

140387521 is a deficient number, since it is larger than the sum of its proper divisors (4840979).

140387521 is an equidigital number, since it uses as much as digits as its factorization.

140387521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4840978.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 140387521 is about 11848.5240009041. The cubic root of 140387521 is about 519.7280641759.

The spelling of 140387521 in words is "one hundred forty million, three hundred eighty-seven thousand, five hundred twenty-one".