1642421547761 has 2 divisors, whose sum is σ = 1642421547762. Its totient is φ = 1642421547760.

The previous prime is 1642421547727. The next prime is 1642421547773. The reversal of 1642421547761 is 1677451242461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 959947293361 + 682474254400 = 979769^2 + 826120^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1642421547761 is a prime.

It is a super-2 number, since 2×1642421547761² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1642421549761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821210773880 + 821210773881.

It is an arithmetic number, because the mean of its divisors is an integer number (821210773881).

Almost surely, 2^{1642421547761} is an apocalyptic number.

It is an amenable number.

1642421547761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1642421547761 is an equidigital number, since it uses as much as digits as its factorization.

1642421547761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2257920, while the sum is 50.

The spelling of 1642421547761 in words is "one trillion, six hundred forty-two billion, four hundred twenty-one million, five hundred forty-seven thousand, seven hundred sixty-one".