53991993 has 8 divisors (see below), whose sum is σ = 78533856. Its totient is φ = 32722400.

The previous prime is 53991979. The next prime is 53992007. The reversal of 53991993 is 39919935.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (53991979) and next prime (53992007).

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

It is a cyclic number.

It is not a de Polignac number, because 53991993 - 2⁶ = 53991929 is a prime.

It is a super-2 number, since 2×53991993² = 5830270616224098, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (53991923) 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, 818028 + ... + 818093.

It is an arithmetic number, because the mean of its divisors is an integer number (9816732).

Almost surely, 2^53991993 is an apocalyptic number.

It is an amenable number.

53991993 is a deficient number, since it is larger than the sum of its proper divisors (24541863).

53991993 is a wasteful number, since it uses less digits than its factorization.

53991993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1636135.

The product of its digits is 295245, while the sum is 48.

The square root of 53991993 is about 7347.9244008087. The cubic root of 53991993 is about 377.9576322157.

The spelling of 53991993 in words is "fifty-three million, nine hundred ninety-one thousand, nine hundred ninety-three".