61010021 has 2 divisors, whose sum is σ = 61010022. Its totient is φ = 61010020.

The previous prime is 61009979. The next prime is 61010023. The reversal of 61010021 is 12001016.

61010021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53085796 + 7924225 = 7286^2 + 2815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61010021 is a prime.

Together with 61010023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 61009984 and 61010011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61010023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30505010 + 30505011.

It is an arithmetic number, because the mean of its divisors is an integer number (30505011).

Almost surely, 2^61010021 is an apocalyptic number.

It is an amenable number.

61010021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61010021 is an equidigital number, since it uses as much as digits as its factorization.

61010021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 61010021 is about 7810.8911783483. The cubic root of 61010021 is about 393.6712732164.

Adding to 61010021 its reverse (12001016), we get a palindrome (73011037).

The spelling of 61010021 in words is "sixty-one million, ten thousand, twenty-one".