11991340 has 24 divisors (see below), whose sum is σ = 25385472. Its totient is φ = 4757760.

The previous prime is 11991313. The next prime is 11991373. The reversal of 11991340 is 4319911.

11991340 = T₃₅ + T₃₆ + ... + T₄₁₅.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 11991299 and 11991308.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180 + ... + 4900.

It is an arithmetic number, because the mean of its divisors is an integer number (1057728).

Almost surely, 2^11991340 is an apocalyptic number.

11991340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11991340 is an abundant number, since it is smaller than the sum of its proper divisors (13394132).

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

11991340 is a wasteful number, since it uses less digits than its factorization.

11991340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4857 (or 4855 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 11991340 is about 3462.8514262093. The cubic root of 11991340 is about 228.8877617830.

It can be divided in two parts, 11991 and 340, that multiplied together give a triangular number (4076940 = T₂₈₅₅).

The spelling of 11991340 in words is "eleven million, nine hundred ninety-one thousand, three hundred forty".