55351021 has 4 divisors (see below), whose sum is σ = 60382944. Its totient is φ = 50319100.

The previous prime is 55350989. The next prime is 55351039. The reversal of 55351021 is 12015355.

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.

It is a cyclic number.

It is not a de Polignac number, because 55351021 - 2⁵ = 55350989 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55350983 and 55351001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55351081) 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, 2515945 + ... + 2515966.

It is an arithmetic number, because the mean of its divisors is an integer number (15095736).

Almost surely, 2^55351021 is an apocalyptic number.

It is an amenable number.

55351021 is a deficient number, since it is larger than the sum of its proper divisors (5031923).

55351021 is a wasteful number, since it uses less digits than its factorization.

55351021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5031922.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 55351021 is about 7439.8266780887. The cubic root of 55351021 is about 381.1025711075.

Adding to 55351021 its reverse (12015355), we get a palindrome (67366376).

It can be divided in two parts, 5535 and 1021, that added together give a palindrome (6556).

The spelling of 55351021 in words is "fifty-five million, three hundred fifty-one thousand, twenty-one".