61221521567 has 2 divisors, whose sum is σ = 61221521568. Its totient is φ = 61221521566.

The previous prime is 61221521549. The next prime is 61221521611. The reversal of 61221521567 is 76512512216.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61221521567 - 2⁸ = 61221521311 is a prime.

It is a super-2 number, since 2×61221521567² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 61221521567.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61221521527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30610760783 + 30610760784.

It is an arithmetic number, because the mean of its divisors is an integer number (30610760784).

Almost surely, 2^61221521567 is an apocalyptic number.

61221521567 is a deficient number, since it is larger than the sum of its proper divisors (1).

61221521567 is an equidigital number, since it uses as much as digits as its factorization.

61221521567 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 38.

The spelling of 61221521567 in words is "sixty-one billion, two hundred twenty-one million, five hundred twenty-one thousand, five hundred sixty-seven".