1221431040 has 216 divisors, whose sum is σ = 4253645760. Its totient is φ = 323592192.

The previous prime is 1221431033. The next prime is 1221431053. The reversal of 1221431040 is 401341221.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2637849 + ... + 2638311.

Almost surely, 2^1221431040 is an apocalyptic number.

1221431040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221431040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2126822880).

1221431040 is an abundant number, since it is smaller than the sum of its proper divisors (3032214720).

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

1221431040 is a wasteful number, since it uses less digits than its factorization.

1221431040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719 (or 702 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1221431040 is about 34948.9776674512. The cubic root of 1221431040 is about 1068.9473561874.

Adding to 1221431040 its reverse (401341221), we get a palindrome (1622772261).

The spelling of 1221431040 in words is "one billion, two hundred twenty-one million, four hundred thirty-one thousand, forty".