551251420021 has 4 divisors (see below), whose sum is σ = 551742295072. Its totient is φ = 550760544972.

The previous prime is 551251420009. The next prime is 551251420037. The reversal of 551251420021 is 120024152155.

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 551251420021 - 2³⁵ = 516891681653 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 (551251420051) 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, 245435841 + ... + 245438086.

It is an arithmetic number, because the mean of its divisors is an integer number (137935573768).

Almost surely, 2^551251420021 is an apocalyptic number.

It is an amenable number.

551251420021 is a deficient number, since it is larger than the sum of its proper divisors (490875051).

551251420021 is a wasteful number, since it uses less digits than its factorization.

551251420021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490875050.

The product of its (nonzero) digits is 4000, while the sum is 28.

Adding to 551251420021 its reverse (120024152155), we get a palindrome (671275572176).

The spelling of 551251420021 in words is "five hundred fifty-one billion, two hundred fifty-one million, four hundred twenty thousand, twenty-one".