1620542146 has 4 divisors (see below), whose sum is σ = 2430813222. Its totient is φ = 810271072.

The previous prime is 1620542137. The next prime is 1620542149. The reversal of 1620542146 is 6412450261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6412450261 = 7 ⋅916064323.

It can be written as a sum of positive squares in only one way, i.e., 1054625625 + 565916521 = 32475^2 + 23789^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1620542149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405135535 + ... + 405135538.

Almost surely, 2^1620542146 is an apocalyptic number.

1620542146 is a deficient number, since it is larger than the sum of its proper divisors (810271076).

1620542146 is an equidigital number, since it uses as much as digits as its factorization.

1620542146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810271075.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 1620542146 is about 40255.9578944533. The cubic root of 1620542146 is about 1174.5912919256.

The spelling of 1620542146 in words is "one billion, six hundred twenty million, five hundred forty-two thousand, one hundred forty-six".