1621537340 has 12 divisors (see below), whose sum is σ = 3405228456. Its totient is φ = 648614928.

The previous prime is 1621537277. The next prime is 1621537361. The reversal of 1621537340 is 437351261.

It is a junction number, because it is equal to n+sod(n) for n = 1621537297 and 1621537306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40538414 + ... + 40538453.

It is an arithmetic number, because the mean of its divisors is an integer number (283769038).

Almost surely, 2^1621537340 is an apocalyptic number.

1621537340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621537340 is an abundant number, since it is smaller than the sum of its proper divisors (1783691116).

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

1621537340 is a wasteful number, since it uses less digits than its factorization.

1621537340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81076876 (or 81076874 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 32.

The square root of 1621537340 is about 40268.3168260110. The cubic root of 1621537340 is about 1174.8316861670.

The spelling of 1621537340 in words is "one billion, six hundred twenty-one million, five hundred thirty-seven thousand, three hundred forty".