1565990400 has 240 divisors, whose sum is σ = 5572862064. Its totient is φ = 385351680.

The previous prime is 1565990399. The next prime is 1565990423. The reversal of 1565990400 is 40995651.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (39).

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, 497632 + ... + 500768.

Almost surely, 2^1565990400 is an apocalyptic number.

1565990400 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 1565990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2786431032).

1565990400 is an abundant number, since it is smaller than the sum of its proper divisors (4006871664).

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

1565990400 is a wasteful number, since it uses less digits than its factorization.

1565990400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3181 (or 3160 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 1565990400 is about 39572.5965789459. The cubic root of 1565990400 is about 1161.2606192323.

The spelling of 1565990400 in words is "one billion, five hundred sixty-five million, nine hundred ninety thousand, four hundred".