1620040881 has 8 divisors (see below), whose sum is σ = 2162521024. Its totient is φ = 1078794000.

The previous prime is 1620040861. The next prime is 1620040897. The reversal of 1620040881 is 1880400261.

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

It is a de Polignac number, because none of the positive numbers 2^k-1620040881 is a prime.

It is a super-2 number, since 2×1620040881² = 5249064912222512322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1620040841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305245 + ... + 310506.

It is an arithmetic number, because the mean of its divisors is an integer number (270315128).

Almost surely, 2^1620040881 is an apocalyptic number.

It is an amenable number.

1620040881 is a deficient number, since it is larger than the sum of its proper divisors (542480143).

1620040881 is an equidigital number, since it uses as much as digits as its factorization.

1620040881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616631.

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 1620040881 is about 40249.7314400978. The cubic root of 1620040881 is about 1174.4701715085.

The spelling of 1620040881 in words is "one billion, six hundred twenty million, forty thousand, eight hundred eighty-one".