1621791040 has 56 divisors (see below), whose sum is σ = 3986491392. Its totient is φ = 627786240.

The previous prime is 1621791023. The next prime is 1621791091. The reversal of 1621791040 is 401971261.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a junction number, because it is equal to n+sod(n) for n = 1621790993 and 1621791011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71824 + ... + 91663.

Almost surely, 2^1621791040 is an apocalyptic number.

1621791040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621791040 is an abundant number, since it is smaller than the sum of its proper divisors (2364700352).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1621791040 is a wasteful number, since it uses less digits than its factorization.

1621791040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163535 (or 163525 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 1621791040 is about 40271.4668220565. The cubic root of 1621791040 is about 1174.8929529761.

The spelling of 1621791040 in words is "one billion, six hundred twenty-one million, seven hundred ninety-one thousand, forty".