61218070561 has 2 divisors, whose sum is σ = 61218070562. Its totient is φ = 61218070560.

The previous prime is 61218070553. The next prime is 61218070583. The reversal of 61218070561 is 16507081216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50156289936 + 11061780625 = 223956^2 + 105175^2 .

It is a cyclic number.

It is not a de Polignac number, because 61218070561 - 2³ = 61218070553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61218070561.

It is not a weakly prime, because it can be changed into another prime (61218070261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30609035280 + 30609035281.

It is an arithmetic number, because the mean of its divisors is an integer number (30609035281).

Almost surely, 2^61218070561 is an apocalyptic number.

It is an amenable number.

61218070561 is a deficient number, since it is larger than the sum of its proper divisors (1).

61218070561 is an equidigital number, since it uses as much as digits as its factorization.

61218070561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 37.

The spelling of 61218070561 in words is "sixty-one billion, two hundred eighteen million, seventy thousand, five hundred sixty-one".