21788142377 has 2 divisors, whose sum is σ = 21788142378. Its totient is φ = 21788142376.

The previous prime is 21788142367. The next prime is 21788142401. The reversal of 21788142377 is 77324188712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16397058601 + 5391083776 = 128051^2 + 73424^2 .

It is a cyclic number.

It is not a de Polignac number, because 21788142377 - 2¹⁴ = 21788125993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21788142367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10894071188 + 10894071189.

It is an arithmetic number, because the mean of its divisors is an integer number (10894071189).

Almost surely, 2^21788142377 is an apocalyptic number.

It is an amenable number.

21788142377 is a deficient number, since it is larger than the sum of its proper divisors (1).

21788142377 is an equidigital number, since it uses as much as digits as its factorization.

21788142377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1053696, while the sum is 50.

The spelling of 21788142377 in words is "twenty-one billion, seven hundred eighty-eight million, one hundred forty-two thousand, three hundred seventy-seven".