1215405400 has 96 divisors (see below), whose sum is σ = 3110626800. Its totient is φ = 437964800.

The previous prime is 1215405371. The next prime is 1215405409. The reversal of 1215405400 is 45045121.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215405409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 246156 + ... + 251044.

Almost surely, 2^1215405400 is an apocalyptic number.

1215405400 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 1215405400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1555313400).

1215405400 is an abundant number, since it is smaller than the sum of its proper divisors (1895221400).

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

1215405400 is a wasteful number, since it uses less digits than its factorization.

1215405400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5029 (or 5020 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 1215405400 is about 34862.6648436404. The cubic root of 1215405400 is about 1067.1866583593.

The spelling of 1215405400 in words is "one billion, two hundred fifteen million, four hundred five thousand, four hundred".