616161 has 32 divisors (see below), whose sum is σ = 1055488. Its totient is φ = 311040.

The previous prime is 616157. The next prime is 616169. The reversal of 616161 is 161616.

616161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 616161 - 2² = 616157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an alternating number because its digits alternate between even and odd.

616161 is an undulating number in base 10.

616161 is a modest number, since divided by 6161 gives 61 as remainder.

It is not an unprimeable number, because it can be changed into a prime (616169) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10071 + ... + 10131.

It is an arithmetic number, because the mean of its divisors is an integer number (32984).

2⁶¹⁶¹⁶¹ is an apocalyptic number.

616161 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

616161 is a deficient number, since it is larger than the sum of its proper divisors (439327).

616161 is a wasteful number, since it uses less digits than its factorization.

616161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121.

The product of its digits is 216, while the sum is 21.

The square root of 616161 is about 784.9592346103. The cubic root of 616161 is about 85.0938294884.

Adding to 616161 its reverse (161616), we get a palindrome (777777).

It can be divided in two parts, 616 and 161, that added together give a palindrome (777).

The spelling of 616161 in words is "six hundred sixteen thousand, one hundred sixty-one".