1215440440 has 16 divisors (see below), whose sum is σ = 2734741080. Its totient is φ = 486176160.

The previous prime is 1215440357. The next prime is 1215440461. The reversal of 1215440440 is 440445121.

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, 15192966 + ... + 15193045.

Almost surely, 2^1215440440 is an apocalyptic number.

1215440440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1215440440 is an abundant number, since it is smaller than the sum of its proper divisors (1519300640).

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

1215440440 is a wasteful number, since it uses less digits than its factorization.

1215440440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30386022 (or 30386018 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

The square root of 1215440440 is about 34863.1673833575. The cubic root of 1215440440 is about 1067.1969138842.

Adding to 1215440440 its reverse (440445121), we get a palindrome (1655885561).

The spelling of 1215440440 in words is "one billion, two hundred fifteen million, four hundred forty thousand, four hundred forty".