1225644501640 has 32 divisors (see below), whose sum is σ = 2969830909080. Its totient is φ = 452545661952.

The previous prime is 1225644501637. The next prime is 1225644501649. The reversal of 1225644501640 is 461054465221.

It can be written as a sum of positive squares in 4 ways, for example, as 962325684324 + 263318817316 = 980982^2 + 513146^2 .

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 = 1225644501593 and 1225644501602.

It is not an unprimeable number, because it can be changed into a prime (1225644501649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1178503809 + ... + 1178504848.

Almost surely, 2^{1225644501640} is an apocalyptic number.

1225644501640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225644501640 is an abundant number, since it is smaller than the sum of its proper divisors (1744186407440).

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

1225644501640 is a wasteful number, since it uses less digits than its factorization.

1225644501640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357008681 (or 2357008677 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 40.

Adding to 1225644501640 its reverse (461054465221), we get a palindrome (1686698966861).

The spelling of 1225644501640 in words is "one trillion, two hundred twenty-five billion, six hundred forty-four million, five hundred one thousand, six hundred forty".