1262401645 has 4 divisors (see below), whose sum is σ = 1514881980. Its totient is φ = 1009921312.

The previous prime is 1262401633. The next prime is 1262401669. The reversal of 1262401645 is 5461042621.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5461042621 = 1901 ⋅2872721.

It can be written as a sum of positive squares in 2 ways, for example, as 180123241 + 1082278404 = 13421^2 + 32898^2 .

It is a cyclic number.

It is not a de Polignac number, because 1262401645 - 2¹⁷ = 1262270573 is a prime.

It is a super-3 number, since 3×1262401645³ (a number of 28 digits) contains 333 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, 126240160 + ... + 126240169.

It is an arithmetic number, because the mean of its divisors is an integer number (378720495).

Almost surely, 2^1262401645 is an apocalyptic number.

It is an amenable number.

1262401645 is a deficient number, since it is larger than the sum of its proper divisors (252480335).

1262401645 is an equidigital number, since it uses as much as digits as its factorization.

1262401645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252480334.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1262401645 is about 35530.2919351924. The cubic root of 1262401645 is about 1080.7680992864.

The spelling of 1262401645 in words is "one billion, two hundred sixty-two million, four hundred one thousand, six hundred forty-five".