53250021 has 32 divisors (see below), whose sum is σ = 88179840. Its totient is φ = 31478400.

The previous prime is 53249983. The next prime is 53250023. The reversal of 53250021 is 12005235.

53250021 = 765² + 766² + ... + 846².

It is a happy number.

It is not a de Polignac number, because 53250021 - 2⁷ = 53249893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 53249976 and 53250003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53250023) 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, 9991 + ... + 14363.

It is an arithmetic number, because the mean of its divisors is an integer number (2755620).

Almost surely, 2^53250021 is an apocalyptic number.

It is an amenable number.

53250021 is a deficient number, since it is larger than the sum of its proper divisors (34929819).

53250021 is a wasteful number, since it uses less digits than its factorization.

53250021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4434 (or 4428 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 53250021 is about 7297.2611985594. The cubic root of 53250021 is about 376.2183096380.

Adding to 53250021 its reverse (12005235), we get a palindrome (65255256).

The spelling of 53250021 in words is "fifty-three million, two hundred fifty thousand, twenty-one".