53991021 has 8 divisors (see below), whose sum is σ = 82272064. Its totient is φ = 30852000.

The previous prime is 53991017. The next prime is 53991053. The reversal of 53991021 is 12019935.

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

It is not a de Polignac number, because 53991021 - 2² = 53991017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 53991021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53991001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1285480 + ... + 1285521.

It is an arithmetic number, because the mean of its divisors is an integer number (10284008).

Almost surely, 2^53991021 is an apocalyptic number.

It is an amenable number.

53991021 is a deficient number, since it is larger than the sum of its proper divisors (28281043).

53991021 is a wasteful number, since it uses less digits than its factorization.

53991021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2571011.

The product of its (nonzero) digits is 2430, while the sum is 30.

The square root of 53991021 is about 7347.8582593842. The cubic root of 53991021 is about 377.9553641200.

The spelling of 53991021 in words is "fifty-three million, nine hundred ninety-one thousand, twenty-one".