1298390840 has 32 divisors (see below), whose sum is σ = 3075138000. Its totient is φ = 492021504.

The previous prime is 1298390831. The next prime is 1298390843. The reversal of 1298390840 is 480938921.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1298390791 and 1298390800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1298390843) 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, 853445 + ... + 854964.

Almost surely, 2^1298390840 is an apocalyptic number.

1298390840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1298390840 is an abundant number, since it is smaller than the sum of its proper divisors (1776747160).

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

1298390840 is a wasteful number, since it uses less digits than its factorization.

1298390840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1708439 (or 1708435 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 1298390840 is about 36033.1908106956. The cubic root of 1298390840 is about 1090.9423828308.

It can be divided in two parts, 12983 and 90840, that added together give a cube (103823 = 47³).

The spelling of 1298390840 in words is "one billion, two hundred ninety-eight million, three hundred ninety thousand, eight hundred forty".