1620857974 has 4 divisors (see below), whose sum is σ = 2431286964. Its totient is φ = 810428986.

The previous prime is 1620857969. The next prime is 1620857977. The reversal of 1620857974 is 4797580261.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620857977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405214492 + ... + 405214495.

It is an arithmetic number, because the mean of its divisors is an integer number (607821741).

Almost surely, 2^1620857974 is an apocalyptic number.

1620857974 is a deficient number, since it is larger than the sum of its proper divisors (810428990).

1620857974 is an equidigital number, since it uses as much as digits as its factorization.

1620857974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810428989.

The product of its (nonzero) digits is 846720, while the sum is 49.

The square root of 1620857974 is about 40259.8804518841. The cubic root of 1620857974 is about 1174.6675924654.

The spelling of 1620857974 in words is "one billion, six hundred twenty million, eight hundred fifty-seven thousand, nine hundred seventy-four".