1221025101 has 12 divisors (see below), whose sum is σ = 1718230752. Its totient is φ = 771173064.

The previous prime is 1221025031. The next prime is 1221025111. The reversal of 1221025101 is 1015201221.

It is not a de Polignac number, because 1221025101 - 2²³ = 1212636493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221025111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 562641 + ... + 564806.

It is an arithmetic number, because the mean of its divisors is an integer number (143185896).

Almost surely, 2^1221025101 is an apocalyptic number.

It is an amenable number.

1221025101 is a deficient number, since it is larger than the sum of its proper divisors (497205651).

1221025101 is a wasteful number, since it uses less digits than its factorization.

1221025101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1127488 (or 1127469 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 1221025101 is about 34943.1695900644. The cubic root of 1221025101 is about 1068.8289225668.

Adding to 1221025101 its reverse (1015201221), we get a palindrome (2236226322).

The spelling of 1221025101 in words is "one billion, two hundred twenty-one million, twenty-five thousand, one hundred one".