1611508397 has 4 divisors (see below), whose sum is σ = 1655062716. Its totient is φ = 1567954080.

The previous prime is 1611508343. The next prime is 1611508399. The reversal of 1611508397 is 7938051161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 908781316 + 702727081 = 30146^2 + 26509^2 .

It is a cyclic number.

It is not a de Polignac number, because 1611508397 - 2³⁰ = 537766573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611508399) 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, 21777104 + ... + 21777177.

It is an arithmetic number, because the mean of its divisors is an integer number (413765679).

Almost surely, 2^1611508397 is an apocalyptic number.

It is an amenable number.

1611508397 is a deficient number, since it is larger than the sum of its proper divisors (43554319).

1611508397 is an equidigital number, since it uses as much as digits as its factorization.

1611508397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43554318.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 1611508397 is about 40143.5972105142. The cubic root of 1611508397 is about 1172.4046283978.

The spelling of 1611508397 in words is "one billion, six hundred eleven million, five hundred eight thousand, three hundred ninety-seven".