1249699920 has 640 divisors, whose sum is σ = 5142528000. Its totient is φ = 249274368.

The previous prime is 1249699877. The next prime is 1249699943. The reversal of 1249699920 is 299969421.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 26589337 + ... + 26589383.

It is an arithmetic number, because the mean of its divisors is an integer number (8035200).

Almost surely, 2^1249699920 is an apocalyptic number.

1249699920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1249699920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2571264000).

1249699920 is an abundant number, since it is smaller than the sum of its proper divisors (3892828080).

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

1249699920 is a wasteful number, since it uses less digits than its factorization.

1249699920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 51.

The square root of 1249699920 is about 35351.0950325446. The cubic root of 1249699920 is about 1077.1311377489.

The spelling of 1249699920 in words is "one billion, two hundred forty-nine million, six hundred ninety-nine thousand, nine hundred twenty".