1953769921 has 2 divisors, whose sum is σ = 1953769922. Its totient is φ = 1953769920.

The previous prime is 1953769879. The next prime is 1953769949. The reversal of 1953769921 is 1299673591.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1913625025 + 40144896 = 43745^2 + 6336^2 .

It is an emirp because it is prime and its reverse (1299673591) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1953769921 is a prime.

It is not a weakly prime, because it can be changed into another prime (1953769721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 976884960 + 976884961.

It is an arithmetic number, because the mean of its divisors is an integer number (976884961).

Almost surely, 2^1953769921 is an apocalyptic number.

It is an amenable number.

1953769921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1953769921 is an equidigital number, since it uses as much as digits as its factorization.

1953769921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 918540, while the sum is 52.

The square root of 1953769921 is about 44201.4696701365. The cubic root of 1953769921 is about 1250.1375680061.

The spelling of 1953769921 in words is "one billion, nine hundred fifty-three million, seven hundred sixty-nine thousand, nine hundred twenty-one".