1565021172 has 96 divisors (see below), whose sum is σ = 4312627200. Its totient is φ = 435473280.

The previous prime is 1565021167. The next prime is 1565021179. The reversal of 1565021172 is 2711205651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1565021179) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 339193 + ... + 343775.

It is an arithmetic number, because the mean of its divisors is an integer number (44923200).

Almost surely, 2^1565021172 is an apocalyptic number.

1565021172 is a gapful number since it is divisible by the number (12) 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 1565021172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2156313600).

1565021172 is an abundant number, since it is smaller than the sum of its proper divisors (2747606028).

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

1565021172 is a wasteful number, since it uses less digits than its factorization.

1565021172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4813 (or 4811 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 30.

The square root of 1565021172 is about 39560.3484817816. The cubic root of 1565021172 is about 1161.0209926905.

The spelling of 1565021172 in words is "one billion, five hundred sixty-five million, twenty-one thousand, one hundred seventy-two".