20151860993 has 4 divisors (see below), whose sum is σ = 21983848368. Its totient is φ = 18319873620.

The previous prime is 20151860977. The next prime is 20151861019. The reversal of 20151860993 is 39906815102.

It is a happy number.

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 20151860993 - 2⁴ = 20151860977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20151860903) 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, 915993671 + ... + 915993692.

It is an arithmetic number, because the mean of its divisors is an integer number (5495962092).

Almost surely, 2^20151860993 is an apocalyptic number.

It is an amenable number.

20151860993 is a deficient number, since it is larger than the sum of its proper divisors (1831987375).

20151860993 is a wasteful number, since it uses less digits than its factorization.

20151860993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1831987374.

The product of its (nonzero) digits is 116640, while the sum is 44.

The spelling of 20151860993 in words is "twenty billion, one hundred fifty-one million, eight hundred sixty thousand, nine hundred ninety-three".