2261661387 has 8 divisors (see below), whose sum is σ = 3045405840. Its totient is φ = 1492845600.

The previous prime is 2261661379. The next prime is 2261661397. The reversal of 2261661387 is 7831661622.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2261661387 - 2³ = 2261661379 is a prime.

It is a super-2 number, since 2×2261661387² = 10230224458893527538, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2261661397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3731812 + ... + 3732417.

It is an arithmetic number, because the mean of its divisors is an integer number (380675730).

Almost surely, 2^2261661387 is an apocalyptic number.

2261661387 is a deficient number, since it is larger than the sum of its proper divisors (783744453).

2261661387 is a wasteful number, since it uses less digits than its factorization.

2261661387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7464333.

The product of its digits is 145152, while the sum is 42.

The square root of 2261661387 is about 47556.9278549403. The cubic root of 2261661387 is about 1312.6306106393.

The spelling of 2261661387 in words is "two billion, two hundred sixty-one million, six hundred sixty-one thousand, three hundred eighty-seven".