1320531990 has 16 divisors (see below), whose sum is σ = 3169276848. Its totient is φ = 352141856.

The previous prime is 1320531973. The next prime is 1320531991. The reversal of 1320531990 is 991350231.

It is a super-2 number, since 2×1320531990² = 3487609473226720200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320531991) 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, 22008837 + ... + 22008896.

It is an arithmetic number, because the mean of its divisors is an integer number (198079803).

Almost surely, 2^1320531990 is an apocalyptic number.

1320531990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1320531990 is an abundant number, since it is smaller than the sum of its proper divisors (1848744858).

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

1320531990 is a wasteful number, since it uses less digits than its factorization.

1320531990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44017743.

The product of its (nonzero) digits is 7290, while the sum is 33.

The square root of 1320531990 is about 36339.1247830764. The cubic root of 1320531990 is about 1097.1086574733.

The spelling of 1320531990 in words is "one billion, three hundred twenty million, five hundred thirty-one thousand, nine hundred ninety".