615994561 has 8 divisors (see below), whose sum is σ = 758147264. Its totient is φ = 487380240.

The previous prime is 615994559. The next prime is 615994571. The reversal of 615994561 is 165499516.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 615994561 - 2¹ = 615994559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (615994501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3384495 + ... + 3384676.

It is an arithmetic number, because the mean of its divisors is an integer number (94768408).

Almost surely, 2^615994561 is an apocalyptic number.

It is an amenable number.

615994561 is a deficient number, since it is larger than the sum of its proper divisors (142152703).

615994561 is a wasteful number, since it uses less digits than its factorization.

615994561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6769191.

The product of its digits is 291600, while the sum is 46.

The square root of 615994561 is about 24819.2377199623. The cubic root of 615994561 is about 850.8616687677.

The spelling of 615994561 in words is "six hundred fifteen million, nine hundred ninety-four thousand, five hundred sixty-one".