61612921 has 2 divisors, whose sum is σ = 61612922. Its totient is φ = 61612920.

The previous prime is 61612891. The next prime is 61612931. The reversal of 61612921 is 12921616.

It is the 3205-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40819321 + 20793600 = 6389^2 + 4560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61612921 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 61612921.

It is not a weakly prime, because it can be changed into another prime (61612931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30806460 + 30806461.

It is an arithmetic number, because the mean of its divisors is an integer number (30806461).

Almost surely, 2^61612921 is an apocalyptic number.

It is an amenable number.

61612921 is a deficient number, since it is larger than the sum of its proper divisors (1).

61612921 is an equidigital number, since it uses as much as digits as its factorization.

61612921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 28.

The square root of 61612921 is about 7849.3898488991. The cubic root of 61612921 is about 394.9637759870.

The spelling of 61612921 in words is "sixty-one million, six hundred twelve thousand, nine hundred twenty-one".