20399661974 has 8 divisors (see below), whose sum is σ = 30604295568. Its totient is φ = 10198230120.

The previous prime is 20399661937. The next prime is 20399661977. The reversal of 20399661974 is 47916699302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20399661974² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20399661977) 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, 784442 + ... + 810029.

It is an arithmetic number, because the mean of its divisors is an integer number (3825536946).

Almost surely, 2^20399661974 is an apocalyptic number.

20399661974 is a deficient number, since it is larger than the sum of its proper divisors (10204633594).

20399661974 is a wasteful number, since it uses less digits than its factorization.

20399661974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1600870.

The product of its (nonzero) digits is 4408992, while the sum is 56.

The spelling of 20399661974 in words is "twenty billion, three hundred ninety-nine million, six hundred sixty-one thousand, nine hundred seventy-four".