1187820720 has 320 divisors, whose sum is σ = 4364006400. Its totient is φ = 296110080.

The previous prime is 1187820703. The next prime is 1187820721. The reversal of 1187820720 is 270287811.

It is a happy number.

It is a super-2 number, since 2×1187820720² = 2821836125722636800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1187820721) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4226980 + ... + 4227260.

It is an arithmetic number, because the mean of its divisors is an integer number (13637520).

Almost surely, 2^1187820720 is an apocalyptic number.

1187820720 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 1187820720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2182003200).

1187820720 is an abundant number, since it is smaller than the sum of its proper divisors (3176185680).

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

1187820720 is a wasteful number, since it uses less digits than its factorization.

1187820720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 1187820720 is about 34464.7750609227. The cubic root of 1187820720 is about 1059.0512217519.

The spelling of 1187820720 in words is "one billion, one hundred eighty-seven million, eight hundred twenty thousand, seven hundred twenty".