53491021 has 4 divisors (see below), whose sum is σ = 53506044. Its totient is φ = 53476000.

The previous prime is 53490989. The next prime is 53491049. The reversal of 53491021 is 12019435.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12019435 = 5 ⋅2403887.

It can be written as a sum of positive squares in 2 ways, for example, as 51122500 + 2368521 = 7150^2 + 1539^2 .

It is a cyclic number.

It is not a de Polignac number, because 53491021 - 2⁵ = 53490989 is a prime.

It is a super-2 number, since 2×53491021² = 5722578655244882, 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 (53491421) 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, 1191 + ... + 10411.

It is an arithmetic number, because the mean of its divisors is an integer number (13376511).

Almost surely, 2^53491021 is an apocalyptic number.

It is an amenable number.

53491021 is a deficient number, since it is larger than the sum of its proper divisors (15023).

53491021 is an equidigital number, since it uses as much as digits as its factorization.

53491021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15022.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 53491021 is about 7313.7556016044. The cubic root of 53491021 is about 376.7850209778.

The spelling of 53491021 in words is "fifty-three million, four hundred ninety-one thousand, twenty-one".