1953216921 has 16 divisors (see below), whose sum is σ = 2758497984. Its totient is φ = 1225096704.

The previous prime is 1953216911. The next prime is 1953216931. The reversal of 1953216921 is 1296123591.

It is an interprime number because it is at equal distance from previous prime (1953216911) and next prime (1953216931).

It is not a de Polignac number, because 1953216921 - 2¹⁵ = 1953184153 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1953216921.

It is not an unprimeable number, because it can be changed into a prime (1953216911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182110 + ... + 192536.

It is an arithmetic number, because the mean of its divisors is an integer number (172406124).

Almost surely, 2^1953216921 is an apocalyptic number.

It is an amenable number.

1953216921 is a deficient number, since it is larger than the sum of its proper divisors (805281063).

1953216921 is a wasteful number, since it uses less digits than its factorization.

1953216921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14120.

The product of its digits is 29160, while the sum is 39.

The square root of 1953216921 is about 44195.2137793223. The cubic root of 1953216921 is about 1250.0196095057.

The spelling of 1953216921 in words is "one billion, nine hundred fifty-three million, two hundred sixteen thousand, nine hundred twenty-one".