20347487 has 4 divisors (see below), whose sum is σ = 21544416. Its totient is φ = 19150560.

The previous prime is 20347469. The next prime is 20347511. The reversal of 20347487 is 78474302.

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

It is a cyclic number.

It is not a de Polignac number, because 20347487 - 2⁸ = 20347231 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20347427) 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, 598439 + ... + 598472.

It is an arithmetic number, because the mean of its divisors is an integer number (5386104).

Almost surely, 2^20347487 is an apocalyptic number.

20347487 is a deficient number, since it is larger than the sum of its proper divisors (1196929).

20347487 is a wasteful number, since it uses less digits than its factorization.

20347487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1196928.

The product of its (nonzero) digits is 37632, while the sum is 35.

The square root of 20347487 is about 4510.8188835288. The cubic root of 20347487 is about 273.0047855253.

The spelling of 20347487 in words is "twenty million, three hundred forty-seven thousand, four hundred eighty-seven".