1620457409 has 4 divisors (see below), whose sum is σ = 1620611520. Its totient is φ = 1620303300.

The previous prime is 1620457379. The next prime is 1620457429. The reversal of 1620457409 is 9047540261.

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 1620457409 - 2¹² = 1620453313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620457429) 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, 60029 + ... + 82730.

It is an arithmetic number, because the mean of its divisors is an integer number (405152880).

Almost surely, 2^1620457409 is an apocalyptic number.

It is an amenable number.

1620457409 is a deficient number, since it is larger than the sum of its proper divisors (154111).

1620457409 is a wasteful number, since it uses less digits than its factorization.

1620457409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154110.

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 1620457409 is about 40254.9054029444. The cubic root of 1620457409 is about 1174.5708187201.

The spelling of 1620457409 in words is "one billion, six hundred twenty million, four hundred fifty-seven thousand, four hundred nine".