249121740 has 384 divisors, whose sum is σ = 926650368. Its totient is φ = 48660480.

The previous prime is 249121709. The next prime is 249121751. The reversal of 249121740 is 47121942.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 249121698 and 249121707.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6076120 + ... + 6076160.

It is an arithmetic number, because the mean of its divisors is an integer number (2413152).

Almost surely, 2^249121740 is an apocalyptic number.

249121740 is a gapful number since it is divisible by the number (20) 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 249121740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (463325184).

249121740 is an abundant number, since it is smaller than the sum of its proper divisors (677528628).

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

249121740 is a wasteful number, since it uses less digits than its factorization.

249121740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 249121740 is about 15783.5908461921. The cubic root of 249121740 is about 629.2219672360.

The spelling of 249121740 in words is "two hundred forty-nine million, one hundred twenty-one thousand, seven hundred forty".