1245021101 has 4 divisors (see below), whose sum is σ = 1285183104. Its totient is φ = 1204859100.

The previous prime is 1245021091. The next prime is 1245021109. The reversal of 1245021101 is 1011205421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1011205421 = 2273 ⋅444877.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1245021101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1245021101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1245021109) 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, 20080955 + ... + 20081016.

It is an arithmetic number, because the mean of its divisors is an integer number (321295776).

Almost surely, 2^1245021101 is an apocalyptic number.

It is an amenable number.

1245021101 is a deficient number, since it is larger than the sum of its proper divisors (40162003).

1245021101 is an equidigital number, since it uses as much as digits as its factorization.

1245021101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40162002.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 1245021101 is about 35284.8565393144. The cubic root of 1245021101 is about 1075.7852135162.

Adding to 1245021101 its reverse (1011205421), we get a palindrome (2256226522).

The spelling of 1245021101 in words is "one billion, two hundred forty-five million, twenty-one thousand, one hundred one".