1616263261 has 4 divisors (see below), whose sum is σ = 1616833024. Its totient is φ = 1615693500.

The previous prime is 1616263237. The next prime is 1616263279. The reversal of 1616263261 is 1623626161.

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: 1623626161 = 29 ⋅55987109.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1616263261 is a prime.

It is a super-2 number, since 2×1616263261² = 5224613857716708242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1616233261) 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, 280605 + ... + 286306.

It is an arithmetic number, because the mean of its divisors is an integer number (404208256).

Almost surely, 2^1616263261 is an apocalyptic number.

It is an amenable number.

1616263261 is a deficient number, since it is larger than the sum of its proper divisors (569763).

1616263261 is an equidigital number, since it uses as much as digits as its factorization.

1616263261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569762.

The product of its digits is 15552, while the sum is 34.

The square root of 1616263261 is about 40202.7767822075. The cubic root of 1616263261 is about 1173.5565824248.

The spelling of 1616263261 in words is "one billion, six hundred sixteen million, two hundred sixty-three thousand, two hundred sixty-one".