1321987770 has 64 divisors (see below), whose sum is σ = 3529008000. Its totient is φ = 352159488.

The previous prime is 1321987769. The next prime is 1321987783. The reversal of 1321987770 is 777891231.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 337986 + ... + 341874.

It is an arithmetic number, because the mean of its divisors is an integer number (55140750).

Almost surely, 2^1321987770 is an apocalyptic number.

1321987770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1321987770 is an abundant number, since it is smaller than the sum of its proper divisors (2207020230).

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

1321987770 is a wasteful number, since it uses less digits than its factorization.

1321987770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5164 (or 5158 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 1321987770 is about 36359.1497425339. The cubic root of 1321987770 is about 1097.5116673469.

The spelling of 1321987770 in words is "one billion, three hundred twenty-one million, nine hundred eighty-seven thousand, seven hundred seventy".