1613612561 has 8 divisors (see below), whose sum is σ = 1774854048. Its totient is φ = 1466919300.

The previous prime is 1613612551. The next prime is 1613612573. The reversal of 1613612561 is 1652163161.

It is not a de Polignac number, because 1613612561 - 2¹⁴ = 1613596177 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1613612501) 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, 604835 + ... + 607496.

It is an arithmetic number, because the mean of its divisors is an integer number (221856756).

Almost surely, 2^1613612561 is an apocalyptic number.

1613612561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1613612561 is a deficient number, since it is larger than the sum of its proper divisors (161241487).

1613612561 is an equidigital number, since it uses as much as digits as its factorization.

1613612561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1212364 (or 1212342 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 1613612561 is about 40169.7966263211. The cubic root of 1613612561 is about 1172.9146802837.

The spelling of 1613612561 in words is "one billion, six hundred thirteen million, six hundred twelve thousand, five hundred sixty-one".