61405650221 has 2 divisors, whose sum is σ = 61405650222. Its totient is φ = 61405650220.

The previous prime is 61405650209. The next prime is 61405650227. The reversal of 61405650221 is 12205650416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55606827721 + 5798822500 = 235811^2 + 76150^2 .

It is a cyclic number.

It is not a de Polignac number, because 61405650221 - 2¹⁴ = 61405633837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61405650227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30702825110 + 30702825111.

It is an arithmetic number, because the mean of its divisors is an integer number (30702825111).

Almost surely, 2^61405650221 is an apocalyptic number.

It is an amenable number.

61405650221 is a deficient number, since it is larger than the sum of its proper divisors (1).

61405650221 is an equidigital number, since it uses as much as digits as its factorization.

61405650221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 32.

The spelling of 61405650221 in words is "sixty-one billion, four hundred five million, six hundred fifty thousand, two hundred twenty-one".