21221210139 has 8 divisors (see below), whose sum is σ = 28309081152. Its totient is φ = 14140406280.

The previous prime is 21221210137. The next prime is 21221210147. The reversal of 21221210139 is 93101212212.

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

It is not a de Polignac number, because 21221210139 - 2¹ = 21221210137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221210137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1759777 + ... + 1771794.

It is an arithmetic number, because the mean of its divisors is an integer number (3538635144).

Almost surely, 2^21221210139 is an apocalyptic number.

21221210139 is a deficient number, since it is larger than the sum of its proper divisors (7087871013).

21221210139 is a wasteful number, since it uses less digits than its factorization.

21221210139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3533577.

The product of its (nonzero) digits is 432, while the sum is 24.

The spelling of 21221210139 in words is "twenty-one billion, two hundred twenty-one million, two hundred ten thousand, one hundred thirty-nine".