1223958640 has 20 divisors (see below), whose sum is σ = 2845704024. Its totient is φ = 489583424.

The previous prime is 1223958581. The next prime is 1223958641. The reversal of 1223958640 is 468593221.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1223958593 and 1223958602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223958641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7649662 + ... + 7649821.

Almost surely, 2^1223958640 is an apocalyptic number.

1223958640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1223958640 is an abundant number, since it is smaller than the sum of its proper divisors (1621745384).

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

1223958640 is a wasteful number, since it uses less digits than its factorization.

1223958640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15299496 (or 15299490 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 1223958640 is about 34985.1202656215. The cubic root of 1223958640 is about 1069.6841994638.

The spelling of 1223958640 in words is "one billion, two hundred twenty-three million, nine hundred fifty-eight thousand, six hundred forty".