1221340434100 has 36 divisors (see below), whose sum is σ = 2650363775584. Its totient is φ = 488526029280.

The previous prime is 1221340434073. The next prime is 1221340434103. The reversal of 1221340434100 is 14340431221.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221340434103) 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, 6368209 + ... + 6557191.

Almost surely, 2^{1221340434100} is an apocalyptic number.

1221340434100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221340434100 is an abundant number, since it is smaller than the sum of its proper divisors (1429023341484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221340434100 is a wasteful number, since it uses less digits than its factorization.

1221340434100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253624 (or 253617 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 1221340434100 its reverse (14340431221), we get a palindrome (1235680865321).

The spelling of 1221340434100 in words is "one trillion, two hundred twenty-one billion, three hundred forty million, four hundred thirty-four thousand, one hundred".