47987309 has 4 divisors (see below), whose sum is σ = 48037404. Its totient is φ = 47937216.

The previous prime is 47987299. The next prime is 47987321. The reversal of 47987309 is 90378974.

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 44262409 + 3724900 = 6653^2 + 1930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-47987309 is a prime.

It is a super-2 number, since 2×47987309² = 4605563650122962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47987399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23582 + ... + 25535.

It is an arithmetic number, because the mean of its divisors is an integer number (12009351).

Almost surely, 2^47987309 is an apocalyptic number.

It is an amenable number.

47987309 is a deficient number, since it is larger than the sum of its proper divisors (50095).

47987309 is an equidigital number, since it uses as much as digits as its factorization.

47987309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50094.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 47987309 is about 6927.2872756946. The cubic root of 47987309 is about 363.3920864690.

The spelling of 47987309 in words is "forty-seven million, nine hundred eighty-seven thousand, three hundred nine".