201730921 has 4 divisors (see below), whose sum is σ = 230549632. Its totient is φ = 172912212.

The previous prime is 201730897. The next prime is 201730927. The reversal of 201730921 is 129037102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 129037102 = 2 ⋅64518551.

It is a cyclic number.

It is not a de Polignac number, because 201730921 - 2⁵ = 201730889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201730927) 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, 14409345 + ... + 14409358.

It is an arithmetic number, because the mean of its divisors is an integer number (57637408).

Almost surely, 2^201730921 is an apocalyptic number.

It is an amenable number.

201730921 is a deficient number, since it is larger than the sum of its proper divisors (28818711).

201730921 is an equidigital number, since it uses as much as digits as its factorization.

201730921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28818710.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 201730921 is about 14203.2010828545. The cubic root of 201730921 is about 586.4857851381.

The spelling of 201730921 in words is "two hundred one million, seven hundred thirty thousand, nine hundred twenty-one".