1225621540 has 48 divisors (see below), whose sum is σ = 3023778240. Its totient is φ = 411396480.

The previous prime is 1225621531. The next prime is 1225621541. The reversal of 1225621540 is 451265221.

It is a junction number, because it is equal to n+sod(n) for n = 1225621499 and 1225621508.

It is not an unprimeable number, because it can be changed into a prime (1225621541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211410 + ... + 217129.

It is an arithmetic number, because the mean of its divisors is an integer number (62995380).

Almost surely, 2^1225621540 is an apocalyptic number.

1225621540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225621540 is an abundant number, since it is smaller than the sum of its proper divisors (1798156700).

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

1225621540 is a wasteful number, since it uses less digits than its factorization.

1225621540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428572 (or 428570 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 1225621540 is about 35008.8780168688. The cubic root of 1225621540 is about 1070.1684132384.

Adding to 1225621540 its reverse (451265221), we get a palindrome (1676886761).

The spelling of 1225621540 in words is "one billion, two hundred twenty-five million, six hundred twenty-one thousand, five hundred forty".