551661001 has 2 divisors, whose sum is σ = 551661002. Its totient is φ = 551661000.

The previous prime is 551660969. The next prime is 551661013. The reversal of 551661001 is 100166155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 469848976 + 81812025 = 21676^2 + 9045^2 .

It is a cyclic number.

It is not a de Polignac number, because 551661001 - 2⁵ = 551660969 is a prime.

It is not a weakly prime, because it can be changed into another prime (551661041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275830500 + 275830501.

It is an arithmetic number, because the mean of its divisors is an integer number (275830501).

Almost surely, 2^551661001 is an apocalyptic number.

It is an amenable number.

551661001 is a deficient number, since it is larger than the sum of its proper divisors (1).

551661001 is an equidigital number, since it uses as much as digits as its factorization.

551661001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 551661001 is about 23487.4647631455. The cubic root of 551661001 is about 820.1452256169.

The spelling of 551661001 in words is "five hundred fifty-one million, six hundred sixty-one thousand, one".