55172152021 has 4 divisors (see below), whose sum is σ = 63053888032. Its totient is φ = 47290416012.

The previous prime is 55172152003. The next prime is 55172152033. The reversal of 55172152021 is 12025127155.

It is a happy number.

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 not a de Polignac number, because 55172152021 - 2⁵ = 55172151989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55172152421) 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 3 ways as a sum of consecutive naturals, for example, 3940867995 + ... + 3940868008.

It is an arithmetic number, because the mean of its divisors is an integer number (15763472008).

Almost surely, 2^55172152021 is an apocalyptic number.

It is an amenable number.

55172152021 is a deficient number, since it is larger than the sum of its proper divisors (7881736011).

55172152021 is an equidigital number, since it uses as much as digits as its factorization.

55172152021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7881736010.

The product of its (nonzero) digits is 7000, while the sum is 31.

Adding to 55172152021 its reverse (12025127155), we get a palindrome (67197279176).

The spelling of 55172152021 in words is "fifty-five billion, one hundred seventy-two million, one hundred fifty-two thousand, twenty-one".