1321021006 has 16 divisors (see below), whose sum is σ = 2098995120. Its totient is φ = 621389440.

The previous prime is 1321020979. The next prime is 1321021007. The reversal of 1321021006 is 6001201231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321021007) 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, 87861 + ... + 101791.

It is an arithmetic number, because the mean of its divisors is an integer number (131187195).

Almost surely, 2^1321021006 is an apocalyptic number.

1321021006 is a deficient number, since it is larger than the sum of its proper divisors (777974114).

1321021006 is a wasteful number, since it uses less digits than its factorization.

1321021006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16739.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1321021006 is about 36345.8526657444. The cubic root of 1321021006 is about 1097.2440669091.

Adding to 1321021006 its reverse (6001201231), we get a palindrome (7322222237).

The spelling of 1321021006 in words is "one billion, three hundred twenty-one million, twenty-one thousand, six".