61115921 has 2 divisors, whose sum is σ = 61115922. Its totient is φ = 61115920.

The previous prime is 61115909. The next prime is 61115947. The reversal of 61115921 is 12951116.

It is an a-pointer prime, because the next prime (61115947) can be obtained adding 61115921 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42315025 + 18800896 = 6505^2 + 4336^2 .

It is a cyclic number.

It is not a de Polignac number, because 61115921 - 2¹⁰ = 61114897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61115521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30557960 + 30557961.

It is an arithmetic number, because the mean of its divisors is an integer number (30557961).

Almost surely, 2^61115921 is an apocalyptic number.

It is an amenable number.

61115921 is a deficient number, since it is larger than the sum of its proper divisors (1).

61115921 is an equidigital number, since it uses as much as digits as its factorization.

61115921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 26.

The square root of 61115921 is about 7817.6672351796. The cubic root of 61115921 is about 393.8989171834.

The spelling of 61115921 in words is "sixty-one million, one hundred fifteen thousand, nine hundred twenty-one".