61838243021 has 2 divisors, whose sum is σ = 61838243022. Its totient is φ = 61838243020.

The previous prime is 61838243009. The next prime is 61838243081. The reversal of 61838243021 is 12034283816.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37591393225 + 24246849796 = 193885^2 + 155714^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61838243021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61838243081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30919121510 + 30919121511.

It is an arithmetic number, because the mean of its divisors is an integer number (30919121511).

Almost surely, 2^61838243021 is an apocalyptic number.

It is an amenable number.

61838243021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61838243021 is an equidigital number, since it uses as much as digits as its factorization.

61838243021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55296, while the sum is 38.

The spelling of 61838243021 in words is "sixty-one billion, eight hundred thirty-eight million, two hundred forty-three thousand, twenty-one".