1995319561 has 9 divisors (see below), whose sum is σ = 2106759693. Its totient is φ = 1889498700.

The previous prime is 1995319559. The next prime is 1995319589. The reversal of 1995319561 is 1659135991.

The square root of 1995319561 is 44669.

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

It is not a de Polignac number, because 1995319561 - 2¹ = 1995319559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1995319531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 847536 + ... + 849886.

Almost surely, 2^1995319561 is an apocalyptic number.

1995319561 is the 44669-th square number.

1995319561 is the 22335-th centered octagonal number.

It is an amenable number.

1995319561 is a deficient number, since it is larger than the sum of its proper divisors (111440132).

1995319561 is an frugal number, since it uses more digits than its factorization.

1995319561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4740 (or 2370 counting only the distinct ones).

The product of its digits is 328050, while the sum is 49.

The cubic root of 1995319561 is about 1258.9374516136.

Multiplying 1995319561 by its sum of digits (49), we get a square (97770658489 = 312683²).

The spelling of 1995319561 in words is "one billion, nine hundred ninety-five million, three hundred nineteen thousand, five hundred sixty-one".