1551551161 has 4 divisors (see below), whose sum is σ = 1551647232. Its totient is φ = 1551455092.

The previous prime is 1551551101. The next prime is 1551551171. The reversal of 1551551161 is 1611551551.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1551551161 - 2¹⁷ = 1551420089 is a prime.

It is a super-2 number, since 2×1551551161² = 4814622010400895842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1551551101) 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, 17221 + ... + 58306.

It is an arithmetic number, because the mean of its divisors is an integer number (387911808).

Almost surely, 2^1551551161 is an apocalyptic number.

It is an amenable number.

1551551161 is a deficient number, since it is larger than the sum of its proper divisors (96071).

1551551161 is an equidigital number, since it uses as much as digits as its factorization.

1551551161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96070.

The product of its digits is 3750, while the sum is 31.

The square root of 1551551161 is about 39389.7342082934. The cubic root of 1551551161 is about 1157.6804523462.

The spelling of 1551551161 in words is "one billion, five hundred fifty-one million, five hundred fifty-one thousand, one hundred sixty-one".