21290727670 has 16 divisors (see below), whose sum is σ = 38544834960. Its totient is φ = 8467063264.

The previous prime is 21290727649. The next prime is 21290727671. The reversal of 21290727670 is 7672709212.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21290727671) 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 7 ways as a sum of consecutive naturals, for example, 6151660 + ... + 6155119.

It is an arithmetic number, because the mean of its divisors is an integer number (2409052185).

Almost surely, 2^21290727670 is an apocalyptic number.

21290727670 is a deficient number, since it is larger than the sum of its proper divisors (17254107290).

21290727670 is a wasteful number, since it uses less digits than its factorization.

21290727670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12306959.

The product of its (nonzero) digits is 148176, while the sum is 43.

The spelling of 21290727670 in words is "twenty-one billion, two hundred ninety million, seven hundred twenty-seven thousand, six hundred seventy".