1249155540 has 192 divisors, whose sum is σ = 4071997440. Its totient is φ = 317520000.

The previous prime is 1249155533. The next prime is 1249155629. The reversal of 1249155540 is 455519421.

1249155540 is a `hidden beast` number, since 1 + 24 + 91 + 5 + 5 + 540 = 666.

It is a super-2 number, since 2×1249155540² = 3120779126225383200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 1249155495 and 1249155504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1188015 + ... + 1189065.

It is an arithmetic number, because the mean of its divisors is an integer number (21208320).

Almost surely, 2^1249155540 is an apocalyptic number.

1249155540 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 1249155540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2035998720).

1249155540 is an abundant number, since it is smaller than the sum of its proper divisors (2822841900).

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

1249155540 is a wasteful number, since it uses less digits than its factorization.

1249155540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171 (or 1163 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The square root of 1249155540 is about 35343.3945738097. The cubic root of 1249155540 is about 1076.9747125137.

The spelling of 1249155540 in words is "one billion, two hundred forty-nine million, one hundred fifty-five thousand, five hundred forty".