1261644153 has 64 divisors (see below), whose sum is σ = 2144102400. Its totient is φ = 640949760.

The previous prime is 1261644149. The next prime is 1261644157. The reversal of 1261644153 is 3514461621.

1261644153 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1261644149) and next prime (1261644157).

It is not a de Polignac number, because 1261644153 - 2² = 1261644149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (1261644157) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2240650 + ... + 2241212.

It is an arithmetic number, because the mean of its divisors is an integer number (33501600).

Almost surely, 2^1261644153 is an apocalyptic number.

It is an amenable number.

1261644153 is a deficient number, since it is larger than the sum of its proper divisors (882458247).

1261644153 is a wasteful number, since it uses less digits than its factorization.

1261644153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782.

The product of its digits is 17280, while the sum is 33.

The square root of 1261644153 is about 35519.6305301730. The cubic root of 1261644153 is about 1080.5518878578.

The spelling of 1261644153 in words is "one billion, two hundred sixty-one million, six hundred forty-four thousand, one hundred fifty-three".