1251455545 has 4 divisors (see below), whose sum is σ = 1501746660. Its totient is φ = 1001164432.

The previous prime is 1251455537. The next prime is 1251455567. The reversal of 1251455545 is 5455541521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5455541521 = 503 ⋅10846007.

It can be written as a sum of positive squares in 2 ways, for example, as 255232576 + 996222969 = 15976^2 + 31563^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251455545 - 2³ = 1251455537 is a prime.

It is a super-2 number, since 2×1251455545² = 3132281962222494050, which contains 22 as substring.

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, 125145550 + ... + 125145559.

It is an arithmetic number, because the mean of its divisors is an integer number (375436665).

Almost surely, 2^1251455545 is an apocalyptic number.

It is an amenable number.

1251455545 is a deficient number, since it is larger than the sum of its proper divisors (250291115).

1251455545 is an equidigital number, since it uses as much as digits as its factorization.

1251455545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250291114.

The product of its digits is 100000, while the sum is 37.

The square root of 1251455545 is about 35375.9175852726. The cubic root of 1251455545 is about 1077.6352997162.

The spelling of 1251455545 in words is "one billion, two hundred fifty-one million, four hundred fifty-five thousand, five hundred forty-five".