2138997973 has 4 divisors (see below), whose sum is σ = 2444569120. Its totient is φ = 1833426828.

The previous prime is 2138997961. The next prime is 2138997989. The reversal of 2138997973 is 3797998312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2138997973 - 2¹³ = 2138989781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2138997173) 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, 152785563 + ... + 152785576.

It is an arithmetic number, because the mean of its divisors is an integer number (611142280).

Almost surely, 2^2138997973 is an apocalyptic number.

It is an amenable number.

2138997973 is a deficient number, since it is larger than the sum of its proper divisors (305571147).

2138997973 is an equidigital number, since it uses as much as digits as its factorization.

2138997973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305571146.

The product of its digits is 5143824, while the sum is 58.

The square root of 2138997973 is about 46249.3024055499. The cubic root of 2138997973 is about 1288.4575786096.

The spelling of 2138997973 in words is "two billion, one hundred thirty-eight million, nine hundred ninety-seven thousand, nine hundred seventy-three".