1221138743377 has 32 divisors (see below), whose sum is σ = 1511021445120. Its totient is φ = 964580322240.

The previous prime is 1221138743371. The next prime is 1221138743411. The reversal of 1221138743377 is 7733478311221.

It is a cyclic number.

It is not a de Polignac number, because 1221138743377 - 2¹⁵ = 1221138710609 is a prime.

It is a super-2 number, since 2×1221138743377² (a number of 25 digits) contains 22 as substring.

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 1221138743377.

It is not an unprimeable number, because it can be changed into a prime (1221138743371) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1240627 + ... + 1995352.

It is an arithmetic number, because the mean of its divisors is an integer number (47219420160).

Almost surely, 2^{1221138743377} is an apocalyptic number.

It is an amenable number.

1221138743377 is a deficient number, since it is larger than the sum of its proper divisors (289882701743).

1221138743377 is a wasteful number, since it uses less digits than its factorization.

1221138743377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3236101.

The product of its digits is 1185408, while the sum is 49.

The spelling of 1221138743377 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-eight million, seven hundred forty-three thousand, three hundred seventy-seven".