21770757919 has 2 divisors, whose sum is σ = 21770757920. Its totient is φ = 21770757918.

The previous prime is 21770757917. The next prime is 21770757937. The reversal of 21770757919 is 91975707712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21770757919 - 2¹ = 21770757917 is a prime.

It is a super-2 number, since 2×21770757919² (a number of 21 digits) contains 22 as substring.

Together with 21770757917, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21770757919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21770757917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10885378959 + 10885378960.

It is an arithmetic number, because the mean of its divisors is an integer number (10885378960).

Almost surely, 2^21770757919 is an apocalyptic number.

21770757919 is a deficient number, since it is larger than the sum of its proper divisors (1).

21770757919 is an equidigital number, since it uses as much as digits as its factorization.

21770757919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944810, while the sum is 55.

It can be divided in two parts, 21770 and 757919, that added together give a square (779689 = 883²).

The spelling of 21770757919 in words is "twenty-one billion, seven hundred seventy million, seven hundred fifty-seven thousand, nine hundred nineteen".