21976377541 has 2 divisors, whose sum is σ = 21976377542. Its totient is φ = 21976377540.

The previous prime is 21976377503. The next prime is 21976377551. The reversal of 21976377541 is 14577367912.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21060104641 + 916272900 = 145121^2 + 30270^2 .

It is a cyclic number.

It is not a de Polignac number, because 21976377541 - 2⁷ = 21976377413 is a prime.

It is a super-2 number, since 2×21976377541² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21976377551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10988188770 + 10988188771.

It is an arithmetic number, because the mean of its divisors is an integer number (10988188771).

Almost surely, 2^21976377541 is an apocalyptic number.

It is an amenable number.

21976377541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21976377541 is an equidigital number, since it uses as much as digits as its factorization.

21976377541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2222640, while the sum is 52.

The spelling of 21976377541 in words is "twenty-one billion, nine hundred seventy-six million, three hundred seventy-seven thousand, five hundred forty-one".