1952137101721 has 3 divisors (see below), whose sum is σ = 1952138498911. Its totient is φ = 1952135704532.

The previous prime is 1952137101661. The next prime is 1952137101727. The reversal of 1952137101721 is 1271017312591.

It is a happy number.

The square root of 1952137101721 is 1397189.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1466857677321 + 485279424400 = 1211139^2 + 696620^2 .

It is not a de Polignac number, because 1952137101721 - 2¹¹ = 1952137099673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1952137101727) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 698595 + ... + 2095783.

Almost surely, 2^{1952137101721} is an apocalyptic number.

1952137101721 is the 1397189-th square number.

1952137101721 is the 698595-th centered octagonal number.

It is an amenable number.

1952137101721 is a deficient number, since it is larger than the sum of its proper divisors (1397190).

1952137101721 is an frugal number, since it uses more digits than its factorization.

1952137101721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2794378 (or 1397189 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 40.

The spelling of 1952137101721 in words is "one trillion, nine hundred fifty-two billion, one hundred thirty-seven million, one hundred one thousand, seven hundred twenty-one".