1621861410 has 128 divisors (see below), whose sum is σ = 4358946816. Its totient is φ = 383512320.

The previous prime is 1621861393. The next prime is 1621861433. The reversal of 1621861410 is 141681261.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1970259 + ... + 1971081.

It is an arithmetic number, because the mean of its divisors is an integer number (34054272).

Almost surely, 2^1621861410 is an apocalyptic number.

1621861410 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1621861410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2179473408).

1621861410 is an abundant number, since it is smaller than the sum of its proper divisors (2737085406).

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

1621861410 is a wasteful number, since it uses less digits than its factorization.

1621861410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1040.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1621861410 is about 40272.3405080956. The cubic root of 1621861410 is about 1174.9099457163.

The spelling of 1621861410 in words is "one billion, six hundred twenty-one million, eight hundred sixty-one thousand, four hundred ten".