21770779966 has 8 divisors (see below), whose sum is σ = 35168183064. Its totient is φ = 10048052280.

The previous prime is 21770779957. The next prime is 21770779967. The reversal of 21770779966 is 66997707712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21770779966² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770779967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 418668820 + ... + 418668871.

It is an arithmetic number, because the mean of its divisors is an integer number (4396022883).

Almost surely, 2^21770779966 is an apocalyptic number.

21770779966 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21770779966 is a deficient number, since it is larger than the sum of its proper divisors (13397403098).

21770779966 is a wasteful number, since it uses less digits than its factorization.

21770779966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837337706.

The product of its (nonzero) digits is 14002632, while the sum is 61.

The spelling of 21770779966 in words is "twenty-one billion, seven hundred seventy million, seven hundred seventy-nine thousand, nine hundred sixty-six".