551670021 has 28 divisors (see below), whose sum is σ = 945296352. Its totient is φ = 315237096.

The previous prime is 551669983. The next prime is 551670023. The reversal of 551670021 is 120076155.

It is not a de Polignac number, because 551670021 - 2⁹ = 551669509 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551670023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 48951 + ... + 59156.

It is an arithmetic number, because the mean of its divisors is an integer number (33760584).

Almost surely, 2^551670021 is an apocalyptic number.

It is an amenable number.

551670021 is a deficient number, since it is larger than the sum of its proper divisors (393626331).

551670021 is an equidigital number, since it uses as much as digits as its factorization.

551670021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108132 (or 108117 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 551670021 is about 23487.6567796790. The cubic root of 551670021 is about 820.1496955538.

The spelling of 551670021 in words is "five hundred fifty-one million, six hundred seventy thousand, twenty-one".