1247879540 has 12 divisors (see below), whose sum is σ = 2620547076. Its totient is φ = 499151808.

The previous prime is 1247879539. The next prime is 1247879551. The reversal of 1247879540 is 459787421.

It can be written as a sum of positive squares in 2 ways, for example, as 237529744 + 1010349796 = 15412^2 + 31786^2 .

It is a super-2 number, since 2×1247879540² = 3114406692701223200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31196969 + ... + 31197008.

It is an arithmetic number, because the mean of its divisors is an integer number (218378923).

Almost surely, 2^1247879540 is an apocalyptic number.

1247879540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1247879540 is an abundant number, since it is smaller than the sum of its proper divisors (1372667536).

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

1247879540 is a wasteful number, since it uses less digits than its factorization.

1247879540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62393986 (or 62393984 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 47.

The square root of 1247879540 is about 35325.3384980243. The cubic root of 1247879540 is about 1076.6078812499.

The spelling of 1247879540 in words is "one billion, two hundred forty-seven million, eight hundred seventy-nine thousand, five hundred forty".