1631280 has 80 divisors (see below), whose sum is σ = 5785344. Its totient is φ = 372480.

The previous prime is 1631263. The next prime is 1631297. The reversal of 1631280 is 821361.

It is an interprime number because it is at equal distance from previous prime (1631263) and next prime (1631297).

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×1631280² = 5322148876800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1195 + ... + 2165.

2^1631280 is an apocalyptic number.

1631280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1631280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2892672).

1631280 is an abundant number, since it is smaller than the sum of its proper divisors (4154064).

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

1631280 is a wasteful number, since it uses less digits than its factorization.

1631280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 994 (or 988 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 1631280 is about 1277.2157217949. The cubic root of 1631280 is about 117.7179897752.

The spelling of 1631280 in words is "one million, six hundred thirty-one thousand, two hundred eighty".