1306661400 has 144 divisors (see below), whose sum is σ = 4787204760. Its totient is φ = 316761600.

The previous prime is 1306661393. The next prime is 1306661443. The reversal of 1306661400 is 41666031.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13197 + ... + 52796.

Almost surely, 2^1306661400 is an apocalyptic number.

1306661400 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 1306661400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2393602380).

1306661400 is an abundant number, since it is smaller than the sum of its proper divisors (3480543360).

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

1306661400 is a wasteful number, since it uses less digits than its factorization.

1306661400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66026 (or 66014 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 1306661400 is about 36147.7717155567. The cubic root of 1306661400 is about 1093.2538630353.

The spelling of 1306661400 in words is "one billion, three hundred six million, six hundred sixty-one thousand, four hundred".