61790021 has 2 divisors, whose sum is σ = 61790022. Its totient is φ = 61790020.

The previous prime is 61789999. The next prime is 61790063. The reversal of 61790021 is 12009716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37039396 + 24750625 = 6086^2 + 4975^2 .

It is a cyclic number.

It is not a de Polignac number, because 61790021 - 2¹⁸ = 61527877 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61790221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30895010 + 30895011.

It is an arithmetic number, because the mean of its divisors is an integer number (30895011).

Almost surely, 2^61790021 is an apocalyptic number.

It is an amenable number.

61790021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61790021 is an equidigital number, since it uses as much as digits as its factorization.

61790021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 61790021 is about 7860.6628855333. The cubic root of 61790021 is about 395.3418415555.

Adding to 61790021 its reverse (12009716), we get a palindrome (73799737).

The spelling of 61790021 in words is "sixty-one million, seven hundred ninety thousand, twenty-one".