101213521 has 4 divisors (see below), whose sum is σ = 101474100. Its totient is φ = 100952944.

The previous prime is 101213507. The next prime is 101213533. The reversal of 101213521 is 125312101.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44422225 + 56791296 = 6665^2 + 7536^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101213521 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 101213495 and 101213504.

It is not an unprimeable number, because it can be changed into a prime (101213821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129706 + ... + 130483.

It is an arithmetic number, because the mean of its divisors is an integer number (25368525).

Almost surely, 2^101213521 is an apocalyptic number.

It is an amenable number.

101213521 is a deficient number, since it is larger than the sum of its proper divisors (260579).

101213521 is an equidigital number, since it uses as much as digits as its factorization.

101213521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260578.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 101213521 is about 10060.4930793674. The cubic root of 101213521 is about 466.0288944857.

Adding to 101213521 its reverse (125312101), we get a palindrome (226525622).

The spelling of 101213521 in words is "one hundred one million, two hundred thirteen thousand, five hundred twenty-one".