1221040420450 has 24 divisors (see below), whose sum is σ = 2272796710272. Its totient is φ = 488058850320.

The previous prime is 1221040420441. The next prime is 1221040420469. The reversal of 1221040420450 is 540240401221.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8863914 + ... + 9000613.

It is an arithmetic number, because the mean of its divisors is an integer number (94699862928).

Almost surely, 2^{1221040420450} is an apocalyptic number.

1221040420450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221040420450 is a deficient number, since it is larger than the sum of its proper divisors (1051756289822).

1221040420450 is a wasteful number, since it uses less digits than its factorization.

1221040420450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17865906 (or 17865901 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 1221040420450 its reverse (540240401221), we get a palindrome (1761280821671).

The spelling of 1221040420450 in words is "one trillion, two hundred twenty-one billion, forty million, four hundred twenty thousand, four hundred fifty".