1221012112100 has 72 divisors (see below), whose sum is σ = 2890786394496. Its totient is φ = 443955600000.

The previous prime is 1221012112081. The next prime is 1221012112129. The reversal of 1221012112100 is 12112101221.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10835045 + ... + 10947155.

Almost surely, 2^{1221012112100} is an apocalyptic number.

1221012112100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221012112100 is an abundant number, since it is smaller than the sum of its proper divisors (1669774282396).

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

1221012112100 is a wasteful number, since it uses less digits than its factorization.

1221012112100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122037 (or 122030 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221012112100 its reverse (12112101221), we get a palindrome (1233124213321).

It can be divided in two parts, 12210121 and 12100, that added together give a palindrome (12222221).

The spelling of 1221012112100 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred twelve thousand, one hundred".