1953079621 has 4 divisors (see below), whose sum is σ = 1953443500. Its totient is φ = 1952715744.

The previous prime is 1953079613. The next prime is 1953079631. The reversal of 1953079621 is 1269703591.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 644448996 + 1308630625 = 25386^2 + 36175^2 .

It is a cyclic number.

It is not a de Polignac number, because 1953079621 - 2³ = 1953079613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1953079631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173766 + ... + 184663.

It is an arithmetic number, because the mean of its divisors is an integer number (488360875).

Almost surely, 2^1953079621 is an apocalyptic number.

It is an amenable number.

1953079621 is a deficient number, since it is larger than the sum of its proper divisors (363879).

1953079621 is an equidigital number, since it uses as much as digits as its factorization.

1953079621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363878.

The product of its (nonzero) digits is 102060, while the sum is 43.

The square root of 1953079621 is about 44193.6604163991. The cubic root of 1953079621 is about 1249.9903190717.

The spelling of 1953079621 in words is "one billion, nine hundred fifty-three million, seventy-nine thousand, six hundred twenty-one".