1221420433240 has 128 divisors (see below), whose sum is σ = 3355446182400. Its totient is φ = 390810562560.

The previous prime is 1221420433223. The next prime is 1221420433253. The reversal of 1221420433240 is 423340241221.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 1221420433199 and 1221420433208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1356921 + ... + 2069800.

It is an arithmetic number, because the mean of its divisors is an integer number (26214423300).

Almost surely, 2^{1221420433240} is an apocalyptic number.

1221420433240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221420433240 is an abundant number, since it is smaller than the sum of its proper divisors (2134025749160).

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

1221420433240 is a wasteful number, since it uses less digits than its factorization.

1221420433240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3426825 (or 3426821 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 1221420433240 its reverse (423340241221), we get a palindrome (1644760674461).

The spelling of 1221420433240 in words is "one trillion, two hundred twenty-one billion, four hundred twenty million, four hundred thirty-three thousand, two hundred forty".