1221324016 has 20 divisors (see below), whose sum is σ = 2581435224. Its totient is φ = 555147200.

The previous prime is 1221323927. The next prime is 1221324079. The reversal of 1221324016 is 6104231221.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3469495 + ... + 3469846.

Almost surely, 2^1221324016 is an apocalyptic number.

1221324016 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1221324016 is an abundant number, since it is smaller than the sum of its proper divisors (1360111208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221324016 is a wasteful number, since it uses less digits than its factorization.

1221324016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6939360 (or 6939354 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 1221324016 is about 34947.4464875476. The cubic root of 1221324016 is about 1068.9161342410.

Adding to 1221324016 its reverse (6104231221), we get a palindrome (7325555237).

The spelling of 1221324016 in words is "one billion, two hundred twenty-one million, three hundred twenty-four thousand, sixteen".