61881121 has 2 divisors, whose sum is σ = 61881122. Its totient is φ = 61881120.

The previous prime is 61881059. The next prime is 61881137. The reversal of 61881121 is 12118816.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43296400 + 18584721 = 6580^2 + 4311^2 .

It is a cyclic number.

It is not a de Polignac number, because 61881121 - 2¹³ = 61872929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61881121.

It is not a weakly prime, because it can be changed into another prime (61881821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30940560 + 30940561.

It is an arithmetic number, because the mean of its divisors is an integer number (30940561).

Almost surely, 2^61881121 is an apocalyptic number.

It is an amenable number.

61881121 is a deficient number, since it is larger than the sum of its proper divisors (1).

61881121 is an equidigital number, since it uses as much as digits as its factorization.

61881121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 768, while the sum is 28.

The square root of 61881121 is about 7866.4554279548. The cubic root of 61881121 is about 395.5360366473.

Adding to 61881121 its reverse (12118816), we get a palindrome (73999937).

The spelling of 61881121 in words is "sixty-one million, eight hundred eighty-one thousand, one hundred twenty-one".