525691221 has 64 divisors (see below), whose sum is σ = 860544000. Its totient is φ = 281318400.

The previous prime is 525691219. The next prime is 525691223. The reversal of 525691221 is 122196525.

It is an interprime number because it is at equal distance from previous prime (525691219) and next prime (525691223).

It is not a de Polignac number, because 525691221 - 2¹ = 525691219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (525691223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1588026 + ... + 1588356.

It is an arithmetic number, because the mean of its divisors is an integer number (13446000).

Almost surely, 2^525691221 is an apocalyptic number.

525691221 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

525691221 is a deficient number, since it is larger than the sum of its proper divisors (334852779).

525691221 is a wasteful number, since it uses less digits than its factorization.

525691221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530.

The product of its digits is 10800, while the sum is 33.

The square root of 525691221 is about 22927.9571920396. The cubic root of 525691221 is about 807.0682108459.

The spelling of 525691221 in words is "five hundred twenty-five million, six hundred ninety-one thousand, two hundred twenty-one".