1221240031 has 4 divisors (see below), whose sum is σ = 1332261864. Its totient is φ = 1110218200.

The previous prime is 1221240023. The next prime is 1221240073. The reversal of 1221240031 is 1300421221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1300421221 = 11 ⋅118220111.

It is a cyclic number.

It is not a de Polignac number, because 1221240031 - 2³ = 1221240023 is a prime.

It is a super-2 number, since 2×1221240031² = 2982854426633761922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221239987 and 1221240014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221240011) 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, 55510900 + ... + 55510921.

It is an arithmetic number, because the mean of its divisors is an integer number (333065466).

Almost surely, 2^1221240031 is an apocalyptic number.

1221240031 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221240031 is a deficient number, since it is larger than the sum of its proper divisors (111021833).

1221240031 is a wasteful number, since it uses less digits than its factorization.

1221240031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111021832.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1221240031 is about 34946.2448769535. The cubic root of 1221240031 is about 1068.8916321493.

Adding to 1221240031 its reverse (1300421221), we get a palindrome (2521661252).

The spelling of 1221240031 in words is "one billion, two hundred twenty-one million, two hundred forty thousand, thirty-one".