20147521 has 8 divisors (see below), whose sum is σ = 20820800. Its totient is φ = 19483632.

The previous prime is 20147509. The next prime is 20147539. The reversal of 20147521 is 12574102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20147521 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20147492 and 20147501.

It is not an unprimeable number, because it can be changed into a prime (20147021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2155 + ... + 6703.

It is an arithmetic number, because the mean of its divisors is an integer number (2602600).

Almost surely, 2^20147521 is an apocalyptic number.

It is an amenable number.

20147521 is a deficient number, since it is larger than the sum of its proper divisors (673279).

20147521 is a wasteful number, since it uses less digits than its factorization.

20147521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4695.

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

The square root of 20147521 is about 4488.5990019159. The cubic root of 20147521 is about 272.1075167870.

The spelling of 20147521 in words is "twenty million, one hundred forty-seven thousand, five hundred twenty-one".