1221402040 has 16 divisors (see below), whose sum is σ = 2748154680. Its totient is φ = 488560800.

The previous prime is 1221402037. The next prime is 1221402047. The reversal of 1221402040 is 402041221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221402047) 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, 15267486 + ... + 15267565.

Almost surely, 2^1221402040 is an apocalyptic number.

1221402040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221402040 is an abundant number, since it is smaller than the sum of its proper divisors (1526752640).

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

1221402040 is a wasteful number, since it uses less digits than its factorization.

1221402040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30535062 (or 30535058 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 1221402040 is about 34948.5627744547. The cubic root of 1221402040 is about 1068.9388962423.

Adding to 1221402040 its reverse (402041221), we get a palindrome (1623443261).

The spelling of 1221402040 in words is "one billion, two hundred twenty-one million, four hundred two thousand, forty".