61445821 has 2 divisors, whose sum is σ = 61445822. Its totient is φ = 61445820.

The previous prime is 61445801. The next prime is 61445831. The reversal of 61445821 is 12854416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56040196 + 5405625 = 7486^2 + 2325^2 .

It is a cyclic number.

It is not a de Polignac number, because 61445821 - 2¹¹ = 61443773 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 (61445801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30722910 + 30722911.

It is an arithmetic number, because the mean of its divisors is an integer number (30722911).

Almost surely, 2^61445821 is an apocalyptic number.

It is an amenable number.

61445821 is a deficient number, since it is larger than the sum of its proper divisors (1).

61445821 is an equidigital number, since it uses as much as digits as its factorization.

61445821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7680, while the sum is 31.

The square root of 61445821 is about 7838.7384826897. The cubic root of 61445821 is about 394.6063931491.

The spelling of 61445821 in words is "sixty-one million, four hundred forty-five thousand, eight hundred twenty-one".