1261503145 has 32 divisors (see below), whose sum is σ = 1767617280. Its totient is φ = 846443520.

The previous prime is 1261503127. The next prime is 1261503163. The reversal of 1261503145 is 5413051621.

It is an interprime number because it is at equal distance from previous prime (1261503127) and next prime (1261503163).

It is not a de Polignac number, because 1261503145 - 2⁷ = 1261503017 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 332821 + ... + 336589.

It is an arithmetic number, because the mean of its divisors is an integer number (55238040).

Almost surely, 2^1261503145 is an apocalyptic number.

It is an amenable number.

1261503145 is a deficient number, since it is larger than the sum of its proper divisors (506114135).

1261503145 is a wasteful number, since it uses less digits than its factorization.

1261503145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3985.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 1261503145 is about 35517.6455441517. The cubic root of 1261503145 is about 1080.5116303000.

Adding to 1261503145 its reverse (5413051621), we get a palindrome (6674554766).

The spelling of 1261503145 in words is "one billion, two hundred sixty-one million, five hundred three thousand, one hundred forty-five".