1221520760 has 32 divisors (see below), whose sum is σ = 2750263200. Its totient is φ = 488280960.

The previous prime is 1221520757. The next prime is 1221520799. The reversal of 1221520760 is 670251221.

It is a super-2 number, since 2×1221520760² = 2984225934221955200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55421 + ... + 74259.

It is an arithmetic number, because the mean of its divisors is an integer number (85945725).

Almost surely, 2^1221520760 is an apocalyptic number.

1221520760 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221520760 is an abundant number, since it is smaller than the sum of its proper divisors (1528742440).

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

1221520760 is a wasteful number, since it uses less digits than its factorization.

1221520760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20471 (or 20467 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 1221520760 is about 34950.2612293528. The cubic root of 1221520760 is about 1068.9735286593.

Adding to 1221520760 its reverse (670251221), we get a palindrome (1891771981).

The spelling of 1221520760 in words is "one billion, two hundred twenty-one million, five hundred twenty thousand, seven hundred sixty".