1615352561 has 4 divisors (see below), whose sum is σ = 1617575232. Its totient is φ = 1613129892.

The previous prime is 1615352551. The next prime is 1615352567. The reversal of 1615352561 is 1652535161.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1652535161 = 3343 ⋅494327.

It is a cyclic number.

It is not a de Polignac number, because 1615352561 - 2¹⁰ = 1615351537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1615352567) 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, 1110245 + ... + 1111698.

It is an arithmetic number, because the mean of its divisors is an integer number (404393808).

Almost surely, 2^1615352561 is an apocalyptic number.

It is an amenable number.

1615352561 is a deficient number, since it is larger than the sum of its proper divisors (2222671).

1615352561 is an equidigital number, since it uses as much as digits as its factorization.

1615352561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2222670.

The product of its digits is 27000, while the sum is 35.

The square root of 1615352561 is about 40191.4488542028. The cubic root of 1615352561 is about 1173.3361235424.

The spelling of 1615352561 in words is "one billion, six hundred fifteen million, three hundred fifty-two thousand, five hundred sixty-one".