1321020016 has 20 divisors (see below), whose sum is σ = 2560566024. Its totient is φ = 660228800.

The previous prime is 1321020013. The next prime is 1321020017. The reversal of 1321020016 is 6100201231.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321020013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24186 + ... + 56806.

Almost surely, 2^1321020016 is an apocalyptic number.

1321020016 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1321020016 is a deficient number, since it is larger than the sum of its proper divisors (1239546008).

1321020016 is a wasteful number, since it uses less digits than its factorization.

1321020016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35160 (or 35154 counting only the distinct ones).

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

The square root of 1321020016 is about 36345.8390465814. The cubic root of 1321020016 is about 1097.2437928100.

Adding to 1321020016 its reverse (6100201231), we get a palindrome (7421221247).

The spelling of 1321020016 in words is "one billion, three hundred twenty-one million, twenty thousand, sixteen".