1661151225 has 12 divisors (see below), whose sum is σ = 2746436816. Its totient is φ = 885947280.

The previous prime is 1661151199. The next prime is 1661151229. The reversal of 1661151225 is 5221511661.

It is not a de Polignac number, because 1661151225 - 2⁶ = 1661151161 is a prime.

It is a super-3 number, since 3×1661151225³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1661151192 and 1661151201.

It is not an unprimeable number, because it can be changed into a prime (1661151229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11074267 + ... + 11074416.

Almost surely, 2^1661151225 is an apocalyptic number.

1661151225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1661151225 is a deficient number, since it is larger than the sum of its proper divisors (1085285591).

1661151225 is a wasteful number, since it uses less digits than its factorization.

1661151225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22148696 (or 22148691 counting only the distinct ones).

The product of its digits is 3600, while the sum is 30.

The square root of 1661151225 is about 40757.2229794916. Note that the first 3 decimals coincide. The cubic root of 1661151225 is about 1184.3218003223.

Adding to 1661151225 its reverse (5221511661), we get a palindrome (6882662886).

The spelling of 1661151225 in words is "one billion, six hundred sixty-one million, one hundred fifty-one thousand, two hundred twenty-five".