1221243155342 has 32 divisors (see below), whose sum is σ = 2151220897728. Its totient is φ = 508988814336.

The previous prime is 1221243155309. The next prime is 1221243155387. The reversal of 1221243155342 is 2435513421221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 444158 + ... + 1624734.

It is an arithmetic number, because the mean of its divisors is an integer number (67225653054).

Almost surely, 2^{1221243155342} is an apocalyptic number.

1221243155342 is a deficient number, since it is larger than the sum of its proper divisors (929977742386).

1221243155342 is a wasteful number, since it uses less digits than its factorization.

1221243155342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1182620.

The product of its digits is 57600, while the sum is 35.

Adding to 1221243155342 its reverse (2435513421221), we get a palindrome (3656756576563).

The spelling of 1221243155342 in words is "one trillion, two hundred twenty-one billion, two hundred forty-three million, one hundred fifty-five thousand, three hundred forty-two".