1220691280 has 40 divisors (see below), whose sum is σ = 2839566024. Its totient is φ = 488025600.

The previous prime is 1220691193. The next prime is 1220691281. The reversal of 1220691280 is 821960221.

It can be written as a sum of positive squares in 4 ways, for example, as 685601856 + 535089424 = 26184^2 + 23132^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220691281) 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, 284350 + ... + 288610.

Almost surely, 2^1220691280 is an apocalyptic number.

1220691280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220691280 is an abundant number, since it is smaller than the sum of its proper divisors (1618874744).

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

1220691280 is a wasteful number, since it uses less digits than its factorization.

1220691280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7855 (or 7849 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1220691280 is about 34938.3926361818. The cubic root of 1220691280 is about 1068.7315098656.

The spelling of 1220691280 in words is "one billion, two hundred twenty million, six hundred ninety-one thousand, two hundred eighty".