1221724342144 has 32 divisors (see below), whose sum is σ = 2473804043640. Its totient is φ = 600848033280.

The previous prime is 1221724342079. The next prime is 1221724342159. The reversal of 1221724342144 is 4412434271221.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×1221724342144² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78227614 + ... + 78243229.

Almost surely, 2^{1221724342144} is an apocalyptic number.

It is an amenable number.

1221724342144 is an abundant number, since it is smaller than the sum of its proper divisors (1252079701496).

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

1221724342144 is an equidigital number, since it uses as much as digits as its factorization.

1221724342144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156470918 (or 156470906 counting only the distinct ones).

The product of its digits is 86016, while the sum is 37.

The spelling of 1221724342144 in words is "one trillion, two hundred twenty-one billion, seven hundred twenty-four million, three hundred forty-two thousand, one hundred forty-four".