615959661 has 4 divisors (see below), whose sum is σ = 821279552. Its totient is φ = 410639772.

The previous prime is 615959647. The next prime is 615959699. The reversal of 615959661 is 166959516.

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.

It is not a de Polignac number, because 615959661 - 2⁵ = 615959629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 615959661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (615959611) 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, 102659941 + ... + 102659946.

It is an arithmetic number, because the mean of its divisors is an integer number (205319888).

Almost surely, 2^615959661 is an apocalyptic number.

It is an amenable number.

615959661 is a deficient number, since it is larger than the sum of its proper divisors (205319891).

615959661 is a wasteful number, since it uses less digits than its factorization.

615959661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205319890.

The product of its digits is 437400, while the sum is 48.

The square root of 615959661 is about 24818.5346263634. The cubic root of 615959661 is about 850.8455995603.

The spelling of 615959661 in words is "six hundred fifteen million, nine hundred fifty-nine thousand, six hundred sixty-one".